Science method

Transmission Electron Microscopy (TEM) - Science method

Transmission Electron Microscopy is a microscopic technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it passes through. An image is formed from the interaction of the electrons transmitted through the specimen; the image is magnified and focused onto an imaging device, such as a fluorescent screen, on a layer of photographic film, or to be detected by a sensor such as a CCD camera.
Questions related to Transmission Electron Microscopy (TEM)
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
I am looking for a software (preferentially free) for simulating SAED patterns of different crystal structures at different zone axes. Do you know any software that has all the features and the crystal structure database?
Relevant answer
Answer
What you are looking for is probably a multislice simulation code. There's plenty of them out there, all with their individual strengths and weaknesses, but based on the same principle. Most of them are open source I believe. Packages you could check out for example:
You'd have to have a look at the documentations to check out all available simulation modes and extra capabilities of these codes. I reckon they can all do what you want. I personally use MULTEM for my simulations, but the choice is yours.
Most of those packages come with some sort of interface to crystallographic files (cif) or some other form of building crystal structures internally, but generally building atomic structures is a bit of a separate problem. I believe abTEM has quite a bit of stuff in that regard though. For Multem I have a little repository to assist with the specimen creation as well (https://github.com/ThFriedrich/atomic_specimen_creation). Cif-files you can easily get from the COD (http://www.crystallography.net/cod/) or the Materials Project Database (https://materialsproject.org/)
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
It is the SAED pattern imaged through JEOL TEM.
Relevant answer
Answer
your SEAD pattern has got no spots and no sharp rings.
That is a clear sign, that you have got amorphous material.
For a comparison of SEAD pattern of amorphous and crystalline material please see for example Fig. 5 of at page 11 of full-text document (= page 175 of publication):
See also for example:
and compare with your case...
Best regards
G.M.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
It was just after I started my research. Recently, I am researching graphene, and I would like to know if graphene and graphene oxide can be separated into SEM, TEM, and AFM images.
Relevant answer
Hi @Park Ju Hyun
An effective and cheaper way to distinguish between graphene and graphene oxide is by Raman spectroscopy.
Regards!
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
Who can identify the multi-layered organelles in the TEM image below of a mouse liver?
Relevant answer
Answer
Ravindra Thakkar Prashant Pandey Thank you for your help. I found a similar structure in the following paper and I think it should be lipid droplets or lipidic granules.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
I am looking for the size and shape of AuNPs before its functionalization with biomolecules.
Relevant answer
Answer
I think 10 nM concentration of gold nanoparticle (Au NPs) will work fine for TEM. I recently performed TEM of Au NPs with 30 nM concentration and got well dispersed Au NPs. I used a 30 nM stock solution and dropcasted 10 uL sample on the TEM grid. The sample was left for sometime and the excess solution was then removed using a clean tissue. You can also leave the sample for overnight drying under IR lamp without removing excess sample.
To get a nice TEM image correct sample preparation is very important.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
what is the explanation for this tem image?
Relevant answer
Answer
Hi, thank you all. I prepared some nanoparticles by encapsulating a small organic molecule with dppc in pbs.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
1 answer
I am seeking an high voltage electron gun for electron diffraction in transimission mode, the beam size and current should be ajdjustable. any one can sutggest ome vendor? Thanks a lot
Relevant answer
Answer
There are some vendors that you can find your given electron gun according to your characteristics. please check the following links
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
My bacterium is Aeromonas dhakensis and I had observed very pretty lateral (peritrichous) flagella under oil immersion light microscope using traditional flagellar stain after growing my bacteria on swarming agar for 6 hr. However, when I used the same method to grow bacteria for TEM, I hardly viewed any flagella on my bacteria. The protocol I used for TEM sample preparation is that I used a sterile disposable inoculation loop to take some of the bacteria from the swarming edge very gently and resuspended in sterile distilled water. The suspension was slightly turbid, and I had checked under light microscopy to ensure flagella were still intact on the bacteria. Then, I proceeded with fixation using 4% glutaraldehyde in cacodylate buffer for 30 min at room temperature and 10 uL of the suspension was absorbed onto 300-mesh Formvar-coated copper grid for 10 min, blotted with filter paper, followed by negative staining with 10 uL of 2% PTA solution (pH=7) for 2 min and blotting again. The grid was dried in a dessicator for at least 3 days prior to TEM viewing (Libra 120, Carl Zeiss) at 120 kV. I would be grateful if anyone can share your knowledge with me in which step I might do wrongly in TEM sample preparation that causing my flagella to lose.
Relevant answer
Answer
@ Var St. Jeor, thank you for the suggestion. Yes, I believe fixative can be one of the possibilities to lose flagella as they are very fragile and I have also came across a number of papers that skip the fixative step. I will try to omit fixative to see if it will work out. Thank you vy much!
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
In DLS there were 2 peaks major one centred at 113.9 nm and the other one was at 21.39nm.In DLS we are getting hydrodynamic size and in TEM the size will be real,right?
Relevant answer
Answer
Harsha Haridas e S One question for you to answer. What is the diameter of a hydrogen atom? Why is it relevant to this question?
DLS provides an intensity distribution proportion to r6 (or volume2) whereas TEM provides a number distribution (proportional to r1). TEM will examine the metallic core of the particle ignoring the essential protective and stabilizing layers (can't be seen) whereas DLS will consider the movement and interactions of the entire particle (core + protective layers). They are different but both are correct if the experiment has been conducted correctly. Understand the reasons for the differences and quote a reasonable number of decimal places.
Please explain your TEM sample preparation as artefacts are likely especially if microtoming is involved. Why?
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
This is the TEM of my prepared polymer loaded AgNPs. What could be the first suggestion or explanation of this graph in its low magnification?
Relevant answer
Answer
Technically, the lighter gray would be considered mostly micro-particles based upon the scale marker.There are two phases in sectional view (the discontinuous phase seems like particulites), which seem to be sectioned in some way. These are the light-gray material. And then a continuous phase (the darker material). I (might) consider this a ceramic material, which has not been fired. But I do not know enough about the sample to draw that conclusion.
Another observation: The material looks sectioned in some manner. This sectioning process is revealing very little topography within the sectional view. The very small, dark, nano-particles look almost like a surface contamination, since they exist within both phases, and “on“ rather than “in“ the material
There seems to be some minor amount of topography present, here and there. This gives the image the feel of being either an SEM, or perhaps an STEM image.
Without knowing more about the material, it’s preparation for microscopy, and the microscope used, I cannot say more than this, and I am most assuredly now saying more than I can legitimately say. Some of thsee observations are questionable at best.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
7 answers
Both X-ray diffraction and electron diffraction are techniques that we can use to determine the structure of crystals. I wonder which is better?
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
1 answer
like the picture below
SEM OR TEM
the specific steps???
Relevant answer
Answer
I think you are talking about cell culture and about observation of a surface of cells. In this case you need SEM. You can find "specific steps" by googling "cell culture sem protocol"
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I am learning how to do negative staining on cells for TEM, and I am seeing highly variable shapes/arrangement of nuclei. Is this normal, or did something go wrong with the processing?
Relevant answer
Answer
You are performing positive (not negative) staining.
Nuclei are not spherical and can have varied shape.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
For microemulsion characterization, I get particle size (Z-average d.nm) with DLS around 18-20 nm consistently even after stability studies. Whereas, with TEM analysis with ImageJ, I am getting the particle size (length d.nm) around 105 nm. What could be the possible reason for this difference?
Relevant answer
Answer
You have obtained good results in the determination of the size of microemulsions by the DLS method,
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
can any on please explain this TEM images which i acquired from plant alstonia venenata using synthesized copper nanoparticles
Relevant answer
Answer
Plant extract molecules play the role of ion stabilizers and reducers in the synthesis of nanoparticles. In the TEM image, you can see the crystalline part of the nanoparticle and the organic layer around it. In order to determine the crystalline part, you need to use X-ray diffractometry and use the Scherer equation to calculate the diameter of the crystalline particle.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
Hi I'm doing TEM on EV and I saw this.
I'm wondering if anyone knows what this is.
Thanks
Relevant answer
Answer
Michał Kulus Hi Thanks for your reply. My particles are about 1uM large, I would think it's too big for viruses but I'm not sure.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I am unable to get good contrast on negative staining of RNA-protein complex. There is too much background. However the perimeter of the complex can be marked, yet the contrast is weak as compared to protein TEM images.
Please respond.
Thank you.
Relevant answer
Answer
Hi Deepakash Das,
It does look like artifacts to me. What do you have in the buffer? How exactly did you prepare the grids (did you glow-discharge? dry inbetween steps; which staining agent?)? What size of particle do you expect? Do you have experience with negative staining? If not, a good starting point could be to optimize the conditions for a sample that always works or that you can recognize easily (like worm hemoglobin), before complicating the process with a newly synthesized one.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
Is it possible that morphology of 1D nanostructure is only visible in Transmission Electron Microscopy but not in Field Emission Scanning Electron Microscopy at higher magnification values of order 3,00,000? Can anyone give me an insight on this? Thanks in advance
Relevant answer
Answer
TEM resolution is better, so for really small particles (just a very few nanometers) TEM is better.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
We run nanospheres in our TEM to verify the machine. The person that trained me is now gone and I feel like I am doing something wrong. I was told to use 14 drops DI water with 2 drops BYK (Disperbyk-192) and 2 drops of the nanosphere size standard. The nanospheres still seem to clump together and or do not show up on the grid at all. Is there a better solution to making this?
Relevant answer
Answer
I guess you're diluting simply to attempt to get isolated spheres and that there's no microtoming involved (then you'll get a size distribution of discs, not spheres!). There should not be a problem (other than cost) by measuring a row of particles and dividing by the number of particles to get an average diameter and standard deviation. The distortion of adjoining spheres is tiny (there's a NIST publication written by George Mulholland on this topic for their 100 nm standard) and can be disregarded for verification purposes. Many other techniques and materials for verifying TEM.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
Dear researchers. You are welcomed by a group of researchers from the Kharkiv National University named after V.N. Karazin. Our main areas of research are the physics of thin films and film functional systems. For many years we have been actively working and actively publishing the results. Unfortunately, the events taking place in Kharkiv do not make it possible at the moment to carry out the experimental part of the research: windows are broken at the university, there are problems with communications, and public transport does not work in Kharkov. We are especially concerned that the windows flew out in winter and the water froze. This could destroy the cooling systems. And the equipment itself is mostly from the 80s of the last century. From modern, we hope to have Tescan Vega 3 LMH and Shimadzu xrd 6100. In this regard, we would be happy to participate in equipment recycling programs. We are an active scientific group and if we stay, you can be sure that the donated equipment will be actively used for the benefit of science.
First of all, our scientific group will be glad:
HRTEM. We very much hope that our TEM microscopes have remained operational. But two of them were made in the 80s of the last century. The newest model, Selmi PEM-125K, was made around 2000 and actually repeats devices from the 80s. Yes, these instruments have been modernized by the laboratory. In situ heating and digital registration systems are available. But that leaves the appliances as devices from the 80s. We understand that this is highly unlikely. But we will be happy to renew our fleet of transmission microscopes with something that has long been outdated for the West.
SEM-FIB. There is no such device that allows making lamellas for TEM and cross-sectional studies in Ukraine. But it is precisely this that is critical for many scientists. Again we understand the almost improbability of its receipt
AFM. Atomic force microscopy has many options for creating contrast, which allow you to capture many of the fundamental properties of samples. Unfortunately, we do not have such devices at our disposal. And we have no experience with them. But we would be happy with a workable AFM.
Other equipment used in thin film research
Helium liquefier. The whole university needs this device
Also, the University, which includes many scientific groups, will be highly grateful for any other scientific equipment that will find its application.
If you know about such programs, I will be very grateful for their information. We wish you all health, peace, and reconciliation.
Relevant answer
Answer
Sergei, have a look at Science for Ukraine if you haven't yet, they have plenty of partners and I'm sure if you get in touch with them they will help out in any way they can:
Слава Україні!
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
15 answers
Hello,
I want to encapsulate the plant extract using liposomes. As you can see in the pictures below, the DLS analysis results were good, but the TEM analysis results were not good. Could it be due to sample preparation and staining? What do you think?
I will appreciate if anyone can help me with this.
Relevant answer
Answer
Maryam Vahedi As I indicated above, a picture of your material would be very helpful. If, as you say, it's completely clear, then it's either small (< 100 nm) or index matched. Then we can look at the TEM process as the cause of the problem. Can you use cryo-TEM?
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
10 answers
  • I prepared grids by adding 10 μL bacteriophages (109 pfu/ml) and allowed them to dry on air. I used 1 ml 2% uranyl acetate solution and put grids in it. Then, waited for 1 hour but I did not get any image for my phages.. Could anyone help me?
Relevant answer
Answer
Negative staining is a very old (about 70 years) but still useful method for routine virus visualization. It is very well described in many textbooks, papers, etc. Personally, I prefer this way:
1. Put a droplet (10ul) of viral suspension on parafilm;
2. Put a grid (ultrathin formvar, stabilized with about 1nm of carbon) on the droplet (face side down) and incubate for about 30sec;
3. Pick the grid up with a sharp tweezer, then gently dry it up with filter paper from the edge, and then immediately put the grid (face side down) to a droplet of 1% UA (water solution). Incubate from 20 to 60 sec (depending on the virus), then pick the grid with a sharp tweezer and gently dry it up with filter paper from the edge.
It's necessary to remember that the suspension should be as pure as possible and the film on the grid should be very thin.
Good luck!
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
1 answer
Which of the following will influence the HRTEM image obtained from a crystalline specimen?
The high tension of the TEM
The orientation of the sample
The defocus
The selected area aperture
The spherical aberration coefficient
The thickness of the specimen
Relevant answer
Answer
Hi, did you get the answer to the above question?
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
9 answers
TEM is having a major problem with sample preparation, whereas XRD is relatively easy as far as sample preparation is concerned, I also found a paper in which XRD was a better method as that the TEM.
Relevant answer
Answer
Hi Raghavendra Darji, I agreed with Valentin Bogatu and Gerhard Martens . The crystallite size of the sample can be determined from the broadening of the XRD peaks. Mathematically, the dislocation density (δ) can be calculated using:
δ =1/D2 where D is the crystallite size. The unit is nm–2.
Good luck.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
After synthesis, I kept it for crystalization in the oven for 5-7 days. I have a few questions related to this:
1) Does sonication time affect the edges of MOF
2) at what stage do we take samples for TEM: after synthesis or after crystalization
3) Amount (weight) of MOF used to prepare the TEM grid
Relevant answer
Answer
1. Ultrasound creates areas of compression and tension in the material and therefore the processing time affects the inside and edge of the sample
2. TEM measures the distances between the electron planes of a crystal by Bragg scattering. Therefore, you need to wait for crystallization
3.There is a grid size. Why even more?
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
Hi, I did a TEM analysis for nitrogen-phosphorus doped fibbers. But I have some results that I can't explain. The fiber in the first image has a diameter of 250 nm, why can I see inside the fiber even though the sample is large for TEM?
The second image is a TEM mapping, the sample in (a) has a diameter of 950 nm, the bright-field TEM shows that the electrons can’t pass through the sample, but the elemental mapping shows the elements that form the sample, can anyone explain this? Also, an XPS analysis shows that the sample has an atomic concentration of 85.95, 4.96, and 0.58% for carbon, nitrogen, and phosphorus, respectively, but elemental mapping shows a high elemental concentration for each element. Does anyone have an idea about what's happening here?
Relevant answer
In [1] you can stand on the following explanations:
"For TEM, samples must be cut into very thin cross-sections. This is to allow electrons to pass right through the sample. After being fixed and dehydrated, samples are embedded in hard resin to make them easier to cut. Then, an instrument called an ultramicrotome cuts the samples into ultra-thin slices (100 nm or thinner). TEM samples are also treated with heavy metals to increase the level of contrast in the final image. The parts of the sample that interact strongly with the metals show up as darker areas." It is clear that how much the specimen preparation in TEM is the key steps for analysis and results integrity.
Best regards
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
The pores of zeolite are divided into one-dimensional, two-dimensional, and three-dimensional. In order to easily distinguish the channels in different directions, they are represented by the a-, b-, and c-axis, respectively. Zeolites will show diffraction fringes in TEM characterization and some type of lattice in electron diffraction. Does the blank sandwiched in black lines in diffraction fringe represent the channels of zeolites? If yes, how to determine if the channel is along the a-, b-, or c-axis? If not, what on earth does it stands for, or what information can be obtained from the diffraction fringe?
It will be very appreciated if you can share your experience.
Relevant answer
Answer
This other paper could be also interesting for you:
Best,
Fran
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
Hey all !
I am looking for the best method to prepare microalgal slides for TEM characterization, especially as I am working with nanoparticles.
Thanks all in advance :)
Relevant answer
Answer
Dear Maysan Nashashibi , thanks for sharing this interesting question. It is always a good idea to use the searching box into RG website, often you will get some very valuable informations such as those provided by Aarif Shah . Specially in the first link you can see a good TEM sample preparation protocol for bio-samples with nanoparticles.
That is a generic protocol, and it must be adapted to each sample and to what you want to characterize. For example, it will be different if these nanoparticles (NPs) are in the liquid media, on the microalgae´s surface, or dispersed into the microalgae´s tissues. Problems associated to NPs aggregation will probably happen in the two first scenarios, when the NPs are dispersed into the liquid media and by evaporation of it, they end up on the surface of the algae. Some NP´s could be attached to the algae surface and evaporation of the media could add more from the media. If you are interested about the NP´s already bonded to the microalgae surface, and there are NP´s dispersed into the media around, it would be useful to remove the algae from the media, wash them up with some clean media (bear in mind that this clean media should not remove the bonded NPs from your algae), then dry the algae as explained in the previous links or if it is available, use a TEM cell for liquid samples. Of course, the microalgae must be thin enough to work in transmission mode as pointed by Mohammed Amer Shaheed .
If the microalgae have the NPs inside their tissues, the chances of aggregation by drying are very few, the algae tissues will keep them apart, so that if you finally observe aggregation of NPs, it means -generally- that they were already aggregated before the drying process. Once more, Mohammed advice is key, you will need a very thin section of your algae to let the electrons go through the sample and forming a image. You can get such thin sections embedding the sample into a resin and cutting it with an ultramicrotome. Otherwise, you could use a FIB (Focused Ion Beam), a very focused and thin beam of ions to cut a lamela (a very thin section) of your sample, which is then placed on a TEM holder grid with the help of micromanipulators.
TEM works by transmission, transmission of electrons through the sample, so depending on the density of each part of your sample (the value of Z, the atomic number of the atoms on each part) you will see more or less contrast. For example, if your NPs are metallic, they will be denser than the organic tissue of your microalgae, and a good contrast will be expected. But if your NP´s are light, say carbon NP´s or Si NPs the contrast with the organic matter will be smaller.
It could be very useful, before to go to the TEM, to observe the samples with an optical microscope (may be a confocal, looking for some fluorescence from the NP´s), or a faster option, to use a SEM, specially if you are studying NP´s on the algae surface. Normally you would need to dry up your sample as with TEM, but here -with SEM- you don´t need to worry about sample´s thickness too much. SEM often requires conductive samples or coating your sample with a very thin conductive layer (gold, carbon, iridium...), but modern equipment also let us to use the sample uncoated, thanks to charge removal methods.
Hope this helps. Good luck with your research work and my best wishes.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
7 answers
I have these oxide/metal/oxide sandwich samples that the thickness of it reaches below 100 nm in the areas indicated in the picture. Those are oxide/oxide regions. I am just concerned about structural studies in the aforementioned areas. The thickness of normal areas of the sandwich is around 5 micrometers. The question is:
1. Can I take it directly in the TEM sampler and just search for those areas without any sample preparation?
If not, what kind of sample preparation do you suggest(not expensive methods like Ion milling and FIB?
Relevant answer
Answer
I am happy to announce that the TEM investigation of the sandwich samples was successfully done without any pre-requisite procedures. The results for Al-Mg and Al-Mg-Be sandwich samples is now presented in the following paper:
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
There are these highly stained dark spots on this TEM image I have from a skin biopsy and curious what they are. Wondering why the stain would bind to these (lysosomes?) so intensely. Anyone have any idea what it is?
Relevant answer
Answer
Skin... maybe melanosomes.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
1 answer
Dear colleagues. I am currently searching for any reference or literature about the quantification of the omega phase (hexagonal) in titanium alloys. I am studying a possible case of stress-induced omega and need to justify the increment of this latter. Apart from area calculation through TEM, is there another technique for this?
Best regards
Relevant answer
Answer
The equilibrium HCP and ω hexagonal are sufficiently different crystal structures so they are easy to distinguish by XRD. There are a number of variations on quantitative analysis techniques, the practicality of which depends on the physical state of your samples and the availability of pure standards. A common and relatively easy method is XRD scans followed by whole pattern fitting, such as Rietveld analysis, which would give a quantitative measure of the phase fractions.
Attached is a plot of simulated profiles of hcp and ω Ti.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
8 answers
I would like to know if I it is possible detect H2O2 in Transmission electron microscopy through DAB and osmium tetroxide reaction. Doe anyone know if it is a possible to detect hydrogen peroxide by stain it in bloco and then observe on TEM?
Relevant answer
Answer
hello Joao Paulo,
you can go through this article, they used H2O2 for ultrastructural detection where cerium perhydroxide was identified by TEM.
H2O2 localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
We have a leakage problem in our TEM pneumatic system. A small filter element is leaking air forcing compressor to run more frequently. Is there any solution to this filter leaking like replacement or do we need to change whole assembly as told by our service engineers?
Relevant answer
Answer
Time ON and OFF depends on how much the TEM is being used. On days with heavy use, ON for a couple of minutes (to fill the buffer tank) and OFF for 1-2 hours. On days with light use, ON for a couple of minutes and off for 4-5 hours.
Cheers
B
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I already did TEM/EDX analysis. The results show K factor value, wt% and Atomic%.
How I convert the results by calibrating with ZAF standard.
Example:
Element K factor wt% Atomic%
O 1.455 8.83 14.53
Si 1.000 91.17 85.47
Relevant answer
Answer
Dear Muhammad Aleem Zahid , your question is a bit fuzzy. I believe you made standardless "quantitative" TEM/EDS analysis of Si-O compound and you are not happy with results. You cannot "convert" data you already have. By the way quantification of specimens like yours with TEM/EDS is nearly impossible. Of course if you have suitable (certified?) SiO2 foil to serve as a standard, you may want to try.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
. Depending on the material in nm size , this type of analysis can be quite difficult, as some of the nanomaterials ‘react’ in the electron beam (recrystallise, deform, change crystal structure), leading to vastly different results. To the best of my knowledge, this analysis cannot be done on suspended nano-particles in solution, because the TEM requires high vacuum. A drop of the solution might need to be deposited on a copper grid for analysis in the TEM.
It would be in the best to find a collaborating university with access to a good TEM, preferably with a cold finger (liquid N2 cooled), in case the material is sensitive to the above mentioned changes in the beam. Putting the sample in the high vacuum, or drying it, might also already cause changes. Some samples survive freeze drying.
or I can used TEM with CQD in liqiued form
Relevant answer
Answer
Walaa Almasri Yes, high energy electron beams can damage polymers and living material. You can use cryo-EM and there are some low(er) powered electron microscopes.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
TEM and FESEM are widely used charachterization techniques in the field of material science and we often get noisy dataset while studying the physical behaviour using image analysis and I need to know that which filters other that gaussian blur.
Relevant answer
Answer
In most cases noisy image is a fault of an operator. Proper acquisition gives (almost) nose free image. Noise acceptable only for imaging at highest magnifications or for drifting (beam sensitive) specimens. As was suggested by Grzegorz Cios you may want to talk to operator.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
Hello everyone,
I have to perform electron microscopy without moving my sample between SEM and TEM.
Do you know if there is any model of electron microscope that combines both modes in one equipment and you can be switching between them directly without moving the sample?
Thank you!
Relevant answer
Answer
Many sem/tem makers produce combined instruments. However, the primary instrument is always the better instrument, TEM with SEM attachment -TEM is the best. SEM with TEM attachment - the SEM is the better instrument. For SEM, the TEM stage attachment is often a Backscatter detector turned up-side-down, So the electron probe goes threw the TEM grid to creat an image on the BSE detector.There is always a huge sacrifice when it comes to the add -on. In my experience, separate instrumentation is always best.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
8 answers
I want to analyze the bacterial cell membrane damage via TEM. For the preparation of sample of TEM which chemicals are used? I have read the literature and there are different chemicals.
After fixation with glutaraldehyde and washing with different series of ethanol in ascending order and drying the pellet.
Is the next step is using osmium or better to use acetonitrile and infilter with quetol epoxy resin?
Relevant answer
Answer
- A fast way to see damaged membrane in TEM is to do negative staining:
You make your sample to adhere at the surface of a coated EM grid (formvar for example) then you contrast with uranyl acetate before drying.
You can see the morphology of bacteria and you may see blobs at the surface of bacteria indicating pores and leak of cytoplasm.
- SEM can be also useful and is medium time preparation. It is like the negative staining (morphology and blobs) but in addition you see details of the surface of the bacteria (pores).
You make your sample to adhere at the surface of glass coverslip, you contrast with osmium tetroxide (optional), dehydrate with ethanol then you dry with a critical point dryer or with hexamethyldisilasane. Metal sputtering before observation.
- The longest way is resin embedding and cutting for TEM, taking a week:
After fixation, you contrast with osmium tetroxide then uranyl acetate (optional). You dehydrate with ethanol then you embed in resin (epon for example). After polymerization, you ultracut the block and you contrast the sections on EM grids (uranyl acetate and lead citrate).
For dehydration, acetone or acetonitrile can be used instead of ethanol.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
Stacking Fault Energy, Transmission Electron Microscopy
Relevant answer
Answer
The eqm seperation of two partial dislocations , Burgers vectors b1 and b2 in a long straight extended dislocation is related to the stacking fault energy. For mathematics I recomend you to refer to the book "Electron Microscopy of Thin Christals" written by Hirsch, which is known as the Bible of TEM.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
I want tot find the particle size from TEM images. I m using imageJ.JS software regarding this.
i learn to set scale. but threshold value is not being set. kindly help me for the attached file as well.
Relevant answer
Answer
Hi Anjali Shrivastava . Are your original images in jpg format? It's always best to have them in an uncompressed format (like tiff) when quantifying. With that said, you will need to work with an 8-bit image (the one you posted is RGB). Go to Image>Type>8-bit to do the conversion. You can then threshold your image using one of the automatic algorithms. You probably need to make the image binary so that you can use the watershed operation. Then you can Analyze Particles (make sure you set measurements to include area and/or perimeter).
Here are some videos you can check out re thresholding and measuring size:
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
13 answers
Suppose I want to study the surface profile of a nano-material. Which would be better technique SEM/TEM for investigating surface profile of that nano-material and why? All valuable answers are appreciable.
Relevant answer
Answer
I would argue that for surface and nanotechnology that one technique is essential and that is ESCA/XPS or (at a pinch) Auger. Indeed I wouldn't consider working in this area without access to XPS. Differences between SEM and TEM you can find with a simple Google search. If you need to measure crystal plane spacings I'd be using TEM. Otherwise SEM has been perfectly adequate for all of my nanoparticle work. Remember that with microscopy the sample size is tiny and almost certainly isn't representative of the whole...
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
9 answers
Is it okay if we talk about doing EDS of magnetic samples on TEM 120KV.
Relevant answer
Answer
Xavier: Metals (and other materials) are often examined within A TEM, via thin-sections prepared via grinding polishing techniques. Such techniques and preparation instrumentation are available at delears. Many of these companies (in example:"Struers and Buehler) carry a long list of metal preparation techniques and the needed instrumentation. They will be happy to assist.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
11 answers
TEM 
Relevant answer
Answer
Agree with Sergei Tarasov
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
11 answers
Hi!
I want to obtain SEM images of gold nanoparticles of a diameter in the range of 20 nm, dispersed in solution. When I searched for literature, I couldn't find relavent information on a suitable magnification, resolution and accelarating voltage for this size of nanoparticles in solution though SEM images for 20 nm gold nanoparticles in tissues and cells were available. Information on TEM for 20 nm gold nanoparticles could be found in many articles too. I'm very new to this field and It would be a great help if someone can provide me with a solution or related literature in this regard.
Thank you in advance!
Relevant answer
Answer
Dear Navoda,
The characteristics of magnification, voltage, etc. will depend on the microscope. Each microscope responds differently. An SEM is not the same as a Field Emission SEM. The results are very different; the quality and the possible magnification also. My recommendation is to carry out different tests until the desired quality and magnification are achieved, although this will depend on the microscope.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
What is better to observe organelles and chromatin? Embedding cells in resin or cryo preparations for TEM?
Relevant answer
Answer
Cyo-TEM gives good results near to natural structure whereas structural deformation can occur during TEM sample processing.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
8 answers
Hello,
I have to do some reserach about the preparation of SEM/TEM samples of metal complexes, I can't find anything because they're not usually characterized by microscopic methods.
Any ideas please ?
Relevant answer
Answer
Dear Mohamed Amine Bourouai , in principle there are no reason a metal complex sample can be analysed by SEM or TEM, unless your samples are sensitive when exposed to air or vacuum, while preparing the sample (in air) or while doing the SEM or TEM images (in vacuum). The electron beam can also cause damages in your samples, depending on the beam energy, exposure times and sample sensitivity. In my experience analysing metal complex, mainly single crystals for X-ray diffraction structure resolution, the samples normally came as crystals in the mother waters where they have grown up. Sometimes, a nice crystal while in the liquid media, becomes a completely cracked one when removed from the original liqueur, sometimes these cracks were not evident under an optical microscope, but once the crystal was ready for measurement the diffraction was clearly of broken crystal (close to powder or with blurry spots). To avoid these problems we used some fluorinated oils to mount and manipulate the crystals, and a flow of cold N2 while recording the data. These measures are not applicable to SEM or TEM, but if your samples are sensitive outside the mother waters, you could use -if available at your university main facilities- some SEM or TEM holders for dealing with liquid samples.
If you are interested just in morphological characterization of your samples, you could check them by means of an optical microscope before and after the SEM/TEM analysis if you are afraid of some damage, change, etc.
Preparation is similar in both cases (SEM and TEM), if your metal complexes are solids and dry, just use a small amount (really tiny) on a SEM stub (sample holder) or a TEM grating (in this case the sample amount must be even smaller and ideally the size of the particles smaller than the grating light (the size of the gratings orifices).
If your sample is dispersed in a solution, just pour a drop of this suspension on the SEM or TEM holder, let it evaporate and then load it into the microscope.
If your samples are dielectrics, a thin coat of conductive layer would be needed for SEM.
Hope this helps. Good luck with your research and best wishes.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
Resuspended or pellet, which is the more proper condition for the fixation of cells for TEM?
4% Paraformaldehyde in PBS will be used for the fixation.
Relevant answer
Answer
It depends upon what you are after. Both are very good techniques, but the independent method allows you more freedom in the data for analyzing independent particles.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I'm having trouble getting clear images of my bacteriophage under TEM. The process I've followed thus far is described below. Any help would be appreciated.
I've isolated bacteriophage active against Staphylococcus aureus bacteria from wastewater.
I grew these to high titer by infecting liquid cultures (S. aureus grown to OD600=0.1) with a low dose of bacteriophage (Multiplicity of infection = 0.1 to 0.05) and incubated until lysis was observed ~3-5 hours later.
These lysates were spun down at 5000g for 5 minutes and filtered through 0.22µm filters.
Chloroform was added (0.1 volumes / 1ml in 10ml), mixed, and left to incubate at room temp for 15-20 minutes with inversions every so often.
These were then centrifuged at 3220g for 10 minutes and care was taken to remove the lysate without touching the cell debris and chloroform layers.
We then used ultrafiltration columns (Cytiva: Vivaspoin 20, 100,000 MWCO) to resuspend the phages (trapped on the column membrane) in pure SM-buffer.
30µl of high titer phage was then fixed using paraformaldehyde and sent for TEM.
TEM images are stained with Uranyl acetate.
Please advise.
Thanks, Josh.
Relevant answer
Answer
I agree with Michael J. Benedik . Just a thought: it looks like the darkened area is in the region of the highest phage aggregation. Maybe it is the reason for higher charging? Please note, that the resolution in that region is also affected - drastically reduced.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
9 answers
Is it necessary to perform both SEM and TEM for nanoparticle screening? in some of the PhD thesis, I have seen that some scholars have done only SEM while others have done both SEM and TEM.
Relevant answer
Answer
It really depends on which instrument is available. SEM gives concrete info on the topography/morphology of relatively big nanoparticles. TEM is more suitable for extremely thin specimens (up to 100-200 nm in size). SEM is relatively straightforward and easy to use. TEM requires more specialized training and requires more effort to master it.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
Recently I have started preparing cross-sectional TEM lamella from the bulk sample using FIB. But I am not aware of how to prepare plane view TEM lamella. Actually, I want to cut a piece of the surface from the bulk sample and wield it to the TEM grid for TEM imaging. Can anyone suggest how can I prepare plane view TEM lamella?
Relevant answer
Answer
I do recommend you read this paper:
Plan-view TEM sample preparation with FIB can take just 2-3 hours with this technique. This is the technique that I have been using that for more than 6 years, and my colleague gave that a nice format in this publication.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
What is the precise difference between the mechanism of measurement of XRD, TEM, SEM, and FISEM
Relevant answer
Answer
SEM determines the morphology of the sample. The source of the beam is the excited electrons from the tungsten filament. When the electron beam hits the sample, the interaction of the beam electrons from the filament and the sample atoms generates a variety of signals. Secondary electrons - electrons from the sample itself.Backscattered electrons-beam electrons from the filament that bounce off nuclei of atoms in the sample. The output of the interaction is detected by the backscattered detector. secondary -ray detector.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
8 answers
I'm working with enzyme immobilization on magnetic supports and I can't find specific protocols for characterization of these supports and enzymes after immobilization by microscopy.
Relevant answer
Answer
Dear all, the following documents give detailled experimental procedure in doing characterization of nanoparticles, and the information obtained via each technique. My Regards
10.1039/9781782621867-00001
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
Dear all,
I can access to MIL-100(Fe) nanoMOFs, the TEM images of which suggest an average diameter of about 200 nm. Is it possible to break this material into particles of 50 nm averaged diameter using standard laboratory equipment?
Thank you in advance
Relevant answer
Answer
You can find the method in my papers.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I have plankton samples preserved in Lugol and I am wondering if I pick cells from this sample, and resuspend them in PBS can I then use them for TEM imaging (if I then do the proper TEM prep protocol e.g. with dehydration etc.)?
I am aware that people use Lugol-preserved samples for SEM, but is the ultra structure preserved enough for TEM?
Thanks!
Relevant answer
Answer
Dear Mega,
I'm quite sure this won't work. As far as my experience goes you will not archive satisfactory fixation for ultrastructural analysis with lugol solution. You need proper cross linking fixation with glutaraldehyde or a mixture of formaldehyde and glutaraledhyde, followed by secondary fixation with osmiumtetroxide. I haven't got any experience with plankton, so I can't give you a detailled protocol, but I'm sure you'll find some in literature. When you work with marine organisms it might be a challenge to find a good buffer system for the fixative, depending on how sensitive you specimen are to osmotic changes. Often ist best to use a buffer based on sea salt solutions or the cultivation media (if used).
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
I am working on developing LFIA using gold nanoparticles (in-house Turkevich). DLS data is satisfactory (0.2 pdi) and TEM shows monodisperse GNPs, but after conjugation the size is way higher than the expected increase (my globular protein is 5 nm and GNP is 20 nm but after the conjugation DLS shows 80 nm conjugate again with a good 0.2 pdI.
I did only DLS after conjugatuion, not TEM
there is a 10 nm red shift in the UV-VIS spectrum and a bit drop in intensity peak after conjugation
concentration and PH sweep was performed
the conjugate works well on the LFIA
I am just wondering about what happens to the GNP conjugate?
Is it a normal phenomenon with in-house GNP?
Many thank for sharing your valuable knowledge
Relevant answer
Answer
The nanoparticles should be added to the protein (in excess) solution. Nonetheless, you will always get some aggregation (reduction in color, widening of the LSPR peak, etc.). If your protein has a lot of hydrophobic patches; they will not contribute towards stability. Tween 20 always helps, specially with gold nanoparticles. If the protein is truly covering all the nanoparticles, I have always wondered if a change in refraction index is required to get accurate hydrodynamic diameters.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
I am looking for an alternative analysis or characterization to confirm my catalyst is a nano-catalyst other than TEM. I really appreciate any help you can provide.
Relevant answer
Answer
I guess you can use Zetasizer for the measurement of nanoparticle size dispersed in a liquid medium.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
5 answers
I know that the acceleration voltage and probe current changes the spot size,but how? For instance, reducing the electron beam current diverges the electron beam into the aperture beneath the condenser lens, which transmits lower intensity of electron beam through it. But how does it affects the incident spot size on the specimen? Similarly, how does acceleration voltage changes the spot size?
I have gone through several reference books and literature, but did not get any appropriate explanation. Kindly enlighten me. Thank you!
Relevant answer
Answer
Actually beam current IS a spot size. Just not really good wording from some manufacturers.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I'll soon be working on a project that involves nanoparticles which need to be under anoxic conditions. My collaborators are preparing the samples in an inert glovebox at another institution and sending them to me. The question is, how do I load them into the TEM holder without exposing them to air? I don't have access to a glovebox, but is there a way to jerry-rig a system that would allow me to minimize the time the samples are exposed to air? A colleague mentioned using some kind of container that I could fill with nitrogen, either from compressed N2 or liquid N2, but I'm not sure what kind of container I might use for that purpose. We don't have a vacuum holder, so they will be exposed to atmosphere when I load the actual sample holder into the microscope, but I'm looking to at least try and avoid exposing them during the actual sample loading. Any tips?
Relevant answer
Answer
You can try using an Atmosbag
Load the sample on the TEM support grid in the bag under inert gas with the TEM holder in the bag as well. After sample loading place the grid in the TEM holder. Then place the the TEM holder in an additional double seal ziploc bag inside the atmos bag whilst still under inert gas. You can then remove the left over samples and loading accesories from the Atmosbag. Take the Atmosbag with TEM holder sealed in the additional ziploc bag inside the Atmosbag to the microscope. Tape the opening of the Atmosbag around the TEM goniometer sample entrance. Then fill the Atmosbag with an inert gas and purge for a bit in over pressure to get rid of most of the oxygen. After a while open the ziploc bag with the TEM holder inside and place into the microscope and pump.
This is a pretty involved process but certain nanostructured materials can oxidise very quickly in ambient environments even if passivated.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
I have a query, I want to do TEM of a Polycaprolactone polymer film (~150-180 micro meter thick). I would like to know what is better wet cryo sectioning or dry cryo sectioning. Can anyone suggest the sample preparation method for its TEM analysis.
Relevant answer
Answer
Dear Carolina Leimgruber, sample preparation is really a practical skill, may be a specialized staff is needed. Some hint are given RG thread and the attached files. My Regards
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
Does anyone have an image of a 3-post (A,B,C) TEM copper half grid in low mag mode as viewed on the phosphor screen? I have images of the type of half grid I'm referring to as seen in a binocular scope and also an image of a TEM mesh grid as seen in low mag mode on the phosphor screen for comparison. I need the image for a TEM demo to give attendees a sense of scale.
Relevant answer
Answer
Sheri Singerling photo of the phosphorous screen or low-mag micrograph? Maybe something here will be useful for you...
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
8 answers
What are the possible characterization techniques to confirm the formation of a core-shell nanostructure except for TEM? How can we confirm it using EDX technique?
Relevant answer
Answer
Core shell structure can be confirmed by stereo microscope technique
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
Hello everyone.
For quite some time now we're trying to employ IL-TEM technique in our lab. In this method the catalyst is deposited on TEM grid, some regions on the sample are chosen for detailed investigation, then the grid is placed in electrochemical cell and the accelerated degradation test is performed (several thousand CV scans). After degradation test the sample is placed back in the microscope, and regions chosen before are examined again.
Literature on the topic is rather ambiguous regarding potential ranges, number of scans, methods of holding the TEM grid in the cell.
Recently we've managed to obtain some promising results, but we're still dealing with a massive problem of gold (originating from grid) dissolution and re-deposition on the sample (most visible in image A3_after_2). This problem seems to be dependant on the upper limiting voltage I'm choosing - the higher the voltage the more of a problem gold becomes. Images I'm attaching come from the measurement performed in 0,4 - 1,2 V (RHE) range, with 200 mV/s scan speed in air saturated electrolyte. The sample was removed from cell after 6000 CV scans, examined, then placed back in the cell for another 12000 scans. It was possible to find some places without gold, but the success of a procedure is hugely luck-dependant. During that measurement the sample was held in self-locking tweezers, which were not in contact with electrolyte. Regarding the sample mounting method I tried few things:
1. Sandwiching the sample between 2 glassy carbon plates.
The plates were immersed in the electrolyte. For some reason this method, with same parameters as the tweezer method, resulted in higher gold contamination.
2. Using 3d printed caps to attach the grid to the electrode
No changes in the catalyst were observed. There was no gold either, which suggest problems with the contact
3. Attaching grid to the electrode or the glassy carbon plate with teflon tape.
Same case as 2., no changes.
4. Attaching grid to the gold plate using teflon tape, resulted in massive gold contamination.
I'm more experienced microscopist than electrochemist, so it's more than possible that I made some electrochemistry-related errors (obvious for someone with experience) during my measurements and I would be more than grateful if someone could point them out.
What I'm most interested in is some advice regarding how can I limit gold contamination during the experiment, as well as some general IL-TEM tips.
Relevant answer
Answer
Thanks a lot, I've known the second paper, but the IL-SEM one is new for me. This is actually the first time I see someone mentioning potential degradation of gold as an issue to be aware of in identical-localization microscopy. Their upper potential (1,17 V) seems not to be so far from mine (1,2 V), which for me caused significant gold contamination. Is that 0,3 V really a make-or-break kind of difference? Also, since that paper SEM-based, some gold could precipitate in the form of particles outside of instrument's detection limit.
What I haven't clarified in my first post - I'm conducting the experiments in 0,1 M HClO4.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
I was wondering what number of cells is best for a pellet for TEM sample processing. I believe the best pellets are ~ 1mm^3 in literature, but I wanted to know what worked best for everyone else.
Relevant answer
Answer
Hello,
I would say the more the best! But sometimes you don't have the choice for the (big) size of the sample.
But if the pellet is too big, there will be a problem with resin polymerization because the good resin mixture will not reach the center of the pellet. Same for tissues you need to cut them into small pieces. So the 1mm3 volume is a good start for the embedding of pellets or tissues.
On the opposite, because I am working at an EM facility, people come sometimes with small samples for diverse reasons. It can be subpopulation of cells isolated from a mouse organ for example. Even with cells in culture, I may start with a small sample because cells are treated with very expensive chemical compounds or cytokines. So I don't ask people to treat cells in a culture flask, I can start with a well plate (6, 24-12, even 96).
For small samples, you need to adapt the recipe. For examples: avoid tremendous number of centrifugations where you may lose sample. You can embed the pellet in gelatin/low-melting-point agarose at the start. For polymerization it exists sharp conical molds to concentrate the sample however difficult to manipulate with resin... and gloves and to centrifuge. You can also think about flat embedding on plastic/glass for adherent cells, which avoid all centrifugations.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
15 answers
I calculated particle size from SEM it was around 0.101 um or 101 nm but when I used the TEM for the same sample the average particle size I found is around 6.5 nm.
Relevant answer
Answer
Use the same TEM grid you observed in TEM for SEM observation. Compare results, they should be the same. Otherwise something is very wrong with one of your microscopes. And I would advise to read a bit about basic things in microscopy, such as resolution.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
3 answers
Hello everyone, I'm currently investigating the model diversity of transmission electron microscopes used in biological research. Trying to find out which producer/model would be the best solution currently. The main area is actually conventional biological TEM using sections on grids or single-hole grids and whole mounts (i.e. negative-stained or metal-shadowed) of the particles. I am not really looking into cryo-EM. Any ideas/advice are appreciated.
Best,
Alexander Kudryavtsev
Relevant answer
Answer
I agree with Denis. I've worked with JEOL JEM 1400 TEMs in three different labs, very reliable, minimal maintenance, easy to work with. If 120kV is enough for you, it's a great TEM.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
Can you stain and image (via TEM) bacteriophage directly from lysate? (10^9 PFU/ml suspended in SM-buffer)
Or do phages need to be purified via other means prior to imaging?
Relevant answer
Answer
Joshua Iszatt,
Data below could be helpful:
How do you check methylation status?
Currently, there are three primary methods to identify and quantify DNA methylation. These are: sodium bisulfite conversion and sequencing, differential enzymatic cleavage of DNA, and affinity capture of methylated DNA (1). Restriction enzyme based differential cleavage of methylated DNA is locus-specific.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
6 answers
Same Electron Microscopy
Relevant answer
Answer
Paul, you might try (in any case: no claim for sufficient/comprehensive/excellent content!):
Open access peer-reviewed Edited Volume
Scanning Electron Microscopy
Edited by Viacheslav Kazmiruk
Published: March 9th 2012
DOI: 10.5772/1973 ISBN: 978-953-51-0092-8
eBook (PDF) ISBN: 978-953-51-4329-1
Copyright year: 2012
Also find:
SCANNING ELECTRON MICROSCOPY Copies of transparencies Vikram Jayaram
==>"Introduction Welcome to the lecture training module on scanning electron microscopy. You should read these notes in conjunction with the slides of the presentation. Text passages...."
or
GOODHEW et al (Eds), 2001:
You might try as well Open Access sources like:
SpringerOpen and open access: Applied Microscopy:
Applied Microscopy will start publishing with SpringerOpen in 2019. Content published before the end of 2018 can be found at the society website.
or:
SEM
Scanning Electron Microscope A To Z - Basic Knowledge For Using The SEM
------------------------------
But most Text Books (on SEM) were published subject to a charge:
e.g. (no claim to completeness!):
Author: Anjam Khursheed (NUS, Singapore)
Scanning Electron Microscope Optics and Spectrometers (416 pages)
https://doi.org/10.1142/7094 | November 2010;
SPRINGER:
Authors: Joseph I. Goldstein, Dale E. Newbury, Joseph R. Michael, Nicholas W.M. Ritchie, John Henry J. Scott, David C. Joy
Scanning Electron Microscopy and X-Ray Microanalysis © 2018
-------------------------------------
Author: Anwar Ul-Hamid
A Beginners' Guide to Scanning Electron Microscopy (2018)
("Provides a concise and accessible introduction to the essentials of SEM")
-----------------------------
1st Edition
Scanning Transmission Electron Microscopy Advanced Characterization Methods for Materials Science Applications
Edited by Alina Bruma Copyright Year 2021
ISBN 9780367197360
Published December 21, 2020 by CRC Press
164 Pages 25 Color & 81 B/W Illustrations
& so on....(knowing that this was NOT requested by your question...(;-||)
More results perhaps in 'Deep Net....' Plain Google search does not find more results for Open Access or "free of cost" (Text Book) contents on SEM.
Best wishes and good luck!
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
2 answers
I will be sending liposome samples for TEM analysis. However, they are not able to do negative staining for me. Is it still possible for me to obtain desirable images?
Relevant answer
Answer
In general, cryo-EM is better for such objects. Draying artifacts make negative staining almost useless for such "soft" structures. Dry samples without staining? No way. I'd recommend to look for a cryo-EM facility around.
Good luck!
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
I am asking about a detailed protocol.
Relevant answer
Answer
Cut the ovary tissue in small pieces and fix them in karnonovsky for 4-6 hours and after give 0.1 M phosphate buffer changes and stored the tissue in 0.1 M phosphate buffer under 4 degree in freezer until further processing. You can also contact SAIF Faculty in AIIMS for further processing and photography.
  • asked a question related to Transmission Electron Microscopy (TEM)
Question
4 answers
I have prepared nanoparticle using (3-Aminopropyl)triethoxysilane (APTES), While doing TEM analysis for the prepared nanoprticle. I have encountered too much solvent background, which hinders the particle visibility.
while drop casting. I have noticed silane solution is forming thin sheet on the copper grid
* To avoid this issue i have diluted the sample 5 times. Still the same
* Used tissue paper to remove solution drop from the copper grid after 30 min. Still i faced the same issue. Unable to take good picture. Kindly someone advise me on this. Thanks in advance !
- I have also attached sample TEM image for the reference