ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

Browse by research topic to find out what others in your field are discussing.

Browse Topics

  • Priyanka Roy added an answer in Fungal Culture:
    During fungal spore preservation, why is a 10% solution of skim milk powder used; what's its significance?

    ·Prepare a 10% solution of skim milk and autoclave it.
    ·Grow fungal culture on suitable medium till
    ·Add 2 or 3 ml of sterile skim milk to the culture. Gently
    scrape the surface with a sterile loop to loosen the
    ·Add 0.5 ml of the milk-spore (0.5 m1/4 g) suspension to
    a vial of chilled, sterilized soil. Add the suspension
    slowly and evenly.

    Priyanka Roy

    Thank you all for your kind reply...

    The answer and publication given by Mohammed saleem Ali-shtayeh and Itzhack Polacheck is reasonable... thank's again in helping me in my research work...

    With regards,

    Priyanka Roy.

  • Meha Fatima asked a question in Neurites:
    How to measure neurite length using Neuron J?

    Can anyone please provide info about measuring neurite length using Neuron J. What should be included in the calculations? vertices? tracings? or groups?. Please also explain what are vertices? Many thanks in advance.

  • Nasser Ghaly Yousif added an answer in Regression:
    Any suggestion for third progression colorectal cancer?

    54 year old male with colorectal cancer, after surgery he received radio chemotherapy with oxaliplatin. First regression treated with FOLFIRI, second regression treated with Irinotecan, thrid regression added Avastin!! what we can do for this third regression?

    Nasser Ghaly Yousif

    No, any new histopathology

  • Galina Khachikyan added an answer in Earthquake Forecasting and Geocataclysm:
    What is the relationship between earthquakes and climatic changes?

    What are the effects of climatic changes on the recent earthquake i.e. Hindu Kush earthquake (7.5 magnitude) that struck South Asia on 26 October 2015. What are the other possible causes of this earthquake?

    What are the possible reasons for the increased frequency of the earthquakes? Can anyone suggest the research articles which describe the relationship of climatic changes and earthquakes?

    Galina Khachikyan

    Please, pay attention that the  present Global Warming is accompanied by the  present Global Seismic Activation (figure) .

  • Azazahemad Kureshi asked a question in Antioxidant Assays:
    Anyone have another method for antioxidant activity for plant extracts? Except DPPH, FRAP and ABTS?

    I want literature on antioxidant assays for plant extracts in detail along with mechanism.

  • Laraib Kanwal added an answer in Magnetic Resonance Imaging:
    Can anyone tell MRI de-noising gives better results in filtering domain(NLM filter) or in transform domain(contourlet transform)?

    "NLM filter" is best in filtering domain and "contourlet transform" is better in transform domain

    Laraib Kanwal

    Thanks sir karamjeet, can you tell me how to load MRI image on matlab? I am downloading T1-weighted MRI image from brainweb. The image format is either .mnc or .rawb. Unable to open on matlab

  • Abdelhalim Boukaba added an answer in RNAse:
    Any advice on why am I not able to detect input protein (47kDa) of a ChIP experiment in Western Blot?

    I am doing ChIP of a transcription factor (47kDa) in differentiated hES cells. For the experiment I am using Millipore ChIP kit. We have earlier seen by western blot and immunostaining that upon 36 hrs of differentiation of hES we get homogeneous expression of the protein. But when I am doing the ChIP, I am not able to detect the protein in INPUT sample.
    My ChIP protocol is as follows:

    1. cells fixed with 1% formaldehyde / 10min.

    2. quenched with 0.125M glycine / 10min.

    3. cells collected - washed 3X with PBS (2000RPM / 5min / 4*C) - Flash freeze @ -80*C.

    4. cells lysed in 300ul lysis buffer (SDS lysis buffer + PIC + PMSF + RNAse) - 30min on ice.

    5. sonicated for 20 cycles (30sec on/30sec off) / invert mix and spin after every 5 cycles.

    6. lysed cells + beads + PIC + PMSF + ChIP Dilution Buffer (final volume: 2ml) - pre clearing / 4-6 hrs / 4*C / rotospin: 20RPM.

    7. after pre clearing, beads are pelleted and the supernatant is collected.

    8. 100 ul of supernatant is kept aside as INPUT sample and the rest is taken ahead for ChIP.

    The antibodies used is custom generated and is shown both by immunostaining and western blot to be specific for the protein.

    The lysis and sonication conditions were standardized to give a sheered DNA smear between 500-100 bp with maximum intensity at 300bp.

    the RNase, PIC, PMSF conditions are standardized to get high purity of DNA. (checked by PCI purification of sonicated DNA: 260/280: ~1.84).

    With all these conditions, I am not able to detect the protein (47kDa) in western in INPUT Sample (attaching the INPUT western for the recent trial experiment done)
    The one thing which i think might be causing a problem at the conditions in which i am running the transfer. (120V, 3.00A, 100min, 4*C). And every time I run a transfer I have seen the transfer buffer heating up.
    Do you think this transfer condition is not good for health or there might be something else that i should check.
    By the way, I am using the regular Tris-Glycine transfer buffer.

    Abdelhalim Boukaba

    I think you need to troubleshoot several aspects of your issue and who didn't have.
    Normally, if you boil your crosslinked sample in SDS buffer with DTT or 2-ME for 10 or 15 min it should be OK.There are papers on that and in our lab it works.
    I suggest you do the following
    1/ prepare nuclei but keep the cytoplasmic fraction
    2/ after sonication keep the pellet
    3/ proceed with ChIP but disolve you ChIPped sample in SDS buffer with DTT and boil

    Into the gel load samples from cytoplasmic, sonicated DNA (input), your ChiPped chromatin and also the pellet. Your protein is somewhere

    It's possible that your protein doesn't crosslink to the DNA (some transcription factors don't crosslink to the DNA with formaldehyde you need to double crosslink, other chromatin associated factor also)
    Another issue is that your protein is associated with chromatin regions that are hard to release. Analyzing the pellet would tell you

    Good luck!

  • Fatima Khalid added an answer in Modeller:
    How can I apply cyclic loading in TNO Diana?

    I have to apply a displacement on frame which is varying with time and it is cyclic. I have midas FX+ Modeller

    Fatima Khalid

    I have applied cyclic loading as a base function command (displacement varying with time). I did nonlinear analysis, so i used time steps. But after analysis, the displacement is not showing to and fro motion. I have attached the pictures for reference

    + 1 more attachment

  • Francis Hirsch added an answer in Climate Change:
    Are there authentic published work confidently pinpointing the sole anthropogenic factors contributing to Climate Change?

    Combined natural and anthropogenic factors (geologically recent phenomenon) govern Climate Change. It is, therefore, of paramount importance to discretely recognize the role of humans in Climate Change and to plan efficient strategy to mitigate it.

    Francis Hirsch

    Harry, please tell us the story, in English, of those two skippers who fought about some rope that was "GEKNIPT" or "GESNEDEN".  That's exactly what comes to my mind when reading the latest contributions to our forum!

  • Asha Jyoti Bharati added an answer in Fumigation:
    Can anybody share some experiences of using fumigant 'Incidur' of Henkel Ecolab, Germany; a gluteraldehyde solution in plant tissue culture lab?

    Besides formaldehyde can anybody please suggest me which type of fumigants we can use in plant tissue culture lab? we are thinking of using gluteraldehyde based solution "Incidur" but we don't know its effectiveness in lab and in tissue cultured plants. Please share some experience or suggestions regarding the use of incidur.

    Asha Jyoti Bharati

    Thank you ma'am for your kind reply. we are already using formalin in our lab. but recently there is issue of contamination so we are trying to use other fumigants. so we came across this new fumigant Incidur. we are thinking of using it once in a week. but it is gluteraldehyde based solution therefore want to know that whether this will be safe for the in vitro plants or not. 

  • Shreyas Kuddannaya added an answer in XPS Analysis:
    How to prepare sample for SEM microscopy imaging and XPS analysis of graphene powder sample?

    Graphene in the form of powder. I need to do its SEM and XPS. How to prepare the sample? The limitation in XPS system is that the sample must be less than 1cm2 size so that it can be held in the holder.

    Shreyas Kuddannaya

    Yes. That would be more preferable and commonly used for these techniques.

  • Krishnan Umachandran added an answer in Early Childhood Education:
    What can be the possible drawbacks of a low enrollment ratio to early childhood education (ECE) in a country?

    What can be the implications of a poor public service in the area of child care?

    Krishnan Umachandran

    Reasons can be -

    ECE is not offered in schools that do offer a full five grades, It is also not covered in other than urban areas (remote, rural communities are limited)


  • Ashis Ranjan Bandyopadhyay added an answer in Organic Synthesis:
    What are the methods for drying N,N-Dimethylacetamide (DMA)?

    I would like to make dry DMA. I found that you can dried it with BaO and distilled it under reduced pressure and store it in the presence of molecular sieves 4A, but unfortunately our lab does not have BaO. Do you have any experience on drying DMA? What method are you using?

    Ashis Ranjan Bandyopadhyay

    CaO can also be tried instead of BaO. 

  • Ossama Mohamed Zakaria added an answer in Educational Management:
    How can we determine the role of top management in an educational organization?

    How can we determine the role of top management in an educational organization?

    Ossama Mohamed Zakaria

    Well, there are many factors that may affect and influence the role of the leadership of top administration at any field that can be applied on educations as well.

    please go to this publication:

    J.A. Kok

    Role of leadership in the management of corporate knowledge

    South African journal of Information management

    Vol.5(3) September 2003

  • Asad Masood Qazi added an answer in Software Technology:
    Is there any tool or methodology which helps software engineers to convert their software architecture model to a mathematical model directly?

    I am looking for any technique or tool, which helps the software engineers to convert the problem statement or steps into mathematical model or equation directly ? rather than goes in detail of designing phase of specification phase by using Ontology, KM, etc.

    Asad Masood Qazi

    Dear, have you the above article in English language ?, then please upload.

  • chee ping Tan added an answer in Identification of Plankton:
    Can anyone identify this dinoflagellate species?

    The cells seen here are from a single-cell isolated clonal culture.

    Photos were taken under 100x magnification with the DinoEyes eyepiece.

    Cells are mixed with alive and dead cell. No stain was used.

    Suspected identification is planktonic Prorocentrum sp.

    Link to pictures on OneDrive: http://1drv.ms/1OlCXYS

    Link to short videos on Youtube: https://www.youtube.com/playlist?list=PLPQxhiYaVoNvAsGSIf6o4wIb_B-pVzj8h

    Thank you.

    chee ping Tan

    I did noticed cells of two different morphology, but I am certain that this culture was established from single cell culture.

  • Swati Verma added an answer in Agglomeration:
    How can I avoid the agglomeration of aluminum nano particles while mixing with other compound?

    How can I avoid the agglomeration of aluminum nano particles while mixing with other compound??

    Swati Verma

    Dear Muhammad Usman Munir

    Thanks for reply. yeah , I think this will work. I will perform the experiment by following your idea and then let you know whether it works or not.

    Thanks & regards

    Swati verma

  • Ishag Adam added an answer in Cancer:
    Is cancer related to surgical error?

    Is cancer related to surgical error?

    Ishag Adam

    Thanks Anirudh Kumar Satsangi 

    still  we are seeking a reference 

  • Zelalem Addis asked a question in 293T:
    Is there any difference between HEK293 T cells and HEK293 D cells?

    I am currently working on AAV and I need HEK293 to package the AAV. some groups use 293D cells. I have only 293T cells. Is there any big difference between two cell types.


  • Anand Pai added an answer in Automotive Engineering:
    How does water injector spray works?

    How water injector spray works and the mechanism that can makes it spread into various pattern?

    Anand Pai

    A water injection or fuel injection in the form of a fine mist, into a gaseous media is achieved through atomization.

    The atomization of any fluid depends on

    • Physical properties (like Surface tension, Pressure, Viscosity etc.) of the fluid at the given operating temperature.
    • Properties of the gaseous media (like pressure, density etc.) into which the spray is directed.
    • Geometrical parameters of Nozzles that are normally used for atomization.
  • Mahmoud Omid added an answer in Negative Results:
    Why is there negativity towards publishing negative results?

    Many experimental results never see the light of publication day. For a large number of these, it comes down to the data being “negative”, i.e. the expected and/or wanted effect was not observed. Despite their potential, negative results are repeatedly relegated to the lab books, the drawers and the trash bins. Prof. Dr. Anthony Cerami once said "Many of the biggest discoveries of my career were the results of failure of another research project. ... Failure strikes a negative tone, but it appeared in my personal history that it was an essential experience on the path to important discoveries.".Should researchers publish their negative results?

    Some new journals like "Journal of Negative Results in Biomedicine" or "New Negatives in Plant Science" encouraging researchers to publish their negative results. But as you know, there is a negativity towards negative results. Why negative results not published by journals as freely as positive results? Is it time to publish research “failures”, too?

    + 1 more attachment

    Mahmoud Omid

    Dear Nimata. Thank you for your comments. But I think you should have emphasized that publishing of negative results should be encouraged "if experiment/study was designed and executed properly" to exclude the possibility of flaw in the experiment.  Thank you.

  • Barbara Sawicka added an answer in Livelihoods:
    Do you think that alternative livelihood is very essential rather than upgrading traditional livelihood?

    Why always alternative? -- What's wrong with traditional?

  • K. Prakash Kumar added an answer in Electrical Engineering:
    How does the transmission line parameters vary with cable length?


    While modelling a transmission line, I have considered L',R',C',G' are the inductance per unit length, resistance per unit length, capacitance per unit length and conductance per unit length respectively.

    However, I don't know how does these parameters vary if the length of the transmission line is increased (say doubled).

    Kindly clarify.

    Thank you.

    K. Prakash Kumar

    from the basic formulae for parameters

    R and L are directly proportional to the length.


    here the distance is not the length of the line. it is the distance between conductors or conductor to the earth depending on which capacitance you are calculating. 

    The area in the formula is directly proportional to the length. Keeping the other parameters constant, C is also directly proportional to the length of line.

    When C increases, reactance decreases and hence a longer line draws more current compared to a shorter line.

    So in short, all R,L and C are directly proportional to the length. 

  • Ishag Adam added an answer in Solar Radiation:
    Can anyone suggest findings of the real performance of photo voltaic module?

    The power output from the PV module will be affected with the amount of solar radiation, temperature, ..

    Ishag Adam

    I agree with  you Jorge Morales Pedraza 

    Can  you provide us with  a reference 

  • Anoop Kumar Srivastava added an answer in Conservation Agriculture:
    How can we expand the sink capacity of soil for carbon storage?

    We very often raise  the issue of declining soil fertility on account of depletion in carbon pool of the soil , which probably has equally  revealing  implications on plant health. An enriched carbon pool of soil has has many ecological functions to serve, besides safeguarding the quality of the soil against soil degradation forces. But, our experiences reveal it is probably equally difficult to elevate the carbon storage capacity of the soil, regardless of practices. I have the following set of questions to my learned colleagues to respond:

    * How far different fertilization practices aid in building the carbon pool of soil irreversibly (Not lost back to atmosphere)?

    * How can we ensure what fraction of soil carbon pool is aiding towards soil health and plant health?

    * How can we decide the capacity of different crops to sequester the atmospheric carbon in plant canopy framework?

    * Do you feel carbon pool of soil dictates the carbon storage capacity of plant?

    * How can we correlate the soil carbon pool and ecological service in a given agro-ecosystem?

    * How far conservation agriculture is effective in improving the soil  carbon pool in irrigated areas?

    Anoop Kumar Srivastava

    Friends , let me flag off  another issue . Do you feel bigger  soil  carbon pool means better crop health / performance ?. What fraction  soil carbon pool really dictates the crop performance ?. Does it vary according  to soil type and nature of crop , annual or perennial in nature?

  • Dia Milani asked a question in TRNSYS:
    Anyone knows how to model linear Fresnel reflectors or central receiver (power tower) in TRNSYS?

    Anyone knows how to model linear Fresnel reflectors or central receiver (power tower) in TRNSYS? Is there competent modules in libraries available to purchase?

  • Usha Padmanabhan added an answer in Cell Migration Assays:
    I am doing a transwell cell migration assay and I am having problems to get a significant number of cells to migrate. How can I improve the assay?

    I am using H358 cell line. I plate 5 x 104 cells.I also tired 2x 105. Cells were starved for 24hs prior the assay. The 8um polycarbonate membrane were treated with collagen type I ON, then washed once with PBS.

    *Upper chamber: cells + 0.2%BSA

    *Lower chamber:medium with 5%FBS and HFC 20ng/mL +here I add my drugs as well

    - The assay was performed ON. I have read in several papers that they add growth factors in the bottom chamber. However, I have not found which ones and concentration.

    I appreciate your help!

    Usha Padmanabhan

    I agree that you can increase your cell number.  I also keep my cells in medium (w/o FBS) in the bottom chamber. I did not add any growth factors to the bottom well.

  • Tobi Popoola added an answer in Social Behavior:
    What is the difference between: 1) internal rewards vs. intrinsic rewards; 2) external rewards vs. extrinsic rewards?

    Hi Everyone,

    Recently, I engaged in a conversation with a professor who concluded that intrinsic rewards differ from internal rewards. Moreover, he suggested that extrinsic rewards differ from external rewards. What are the differences (if any)?

    Please include references.

    Thank you.

    Tobi Popoola

    Dear Uco,

    Good point! I currently do not have an answer to your question on my professors conclusion. Thanks for the contribution

  • Ashutosh Jani added an answer in Qualitative Data Analysis:
    Which are different qualitative data analysis techniques ?

    My research is focusing on Qualitative and Quantitative Data collection. I would like to know more about different Qualitative Data Analysis Techniques. How do we go-ahead about Qualitative Data Analysis?

    Ashutosh Jani

    Dear all,

    Yes, my purpose is for Qualitative Analysis. Its a study of empirical collection of data through the interview of participants along with there are 60 questionnaire items on 5 point Likert scale. I have been asked to do the qualitative analysis for my survey data along with interview data collected.