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

  • Tareg Mohammed added an answer in Interleukin-6:
    Any alternative to expensive ELISA kits for IL-6 or other inflammatory markers?

    I need to quantify Interleukin 6 or IL-6 and couple other inflammation markers. The method I want to try is ELISA but ELISA kit is expensive. Any other alternative? 

    Tareg Mohammed · Tohoku University

    If you have a luminex analyzer that would be the most cost effective method when it comes to simultaneous analysis of multiple cytokines. It is not as sensitive to environmental contamination as PCR and up to 100 markers can be analyzed in a single well for the same amount of time needed by most ELISA kits.There are some available comercial kits and you can customize your own assays as well.

  • Fizah Ibrahim added an answer in Transduction:
    How can we confirm that the isolated phage is pure?

    The option is only by PCR or is there any other method? And lytic phage can be confirmed by soft agar method right, is there any method we need to proceed to reconfirm that those phage is lytic type? Do we need to proceed to transduction? I did read paper they proceed to this method to confirm the ability of phage to transduce genetic elements. Does anyone has any experience regarding this method? Thanks very much for your time

    Fizah Ibrahim · Universiti Malaysia Terengganu

    Dear Jay Lee,

    Big thanks for the reply, its nothing late as long as you share your knowledge, highly appreciated :). Anyway, I did experienced the problem like yours, tried to reisolate on soft agar by single plaque but got no result, many times. Is it possible for you to share what induction  studies did you used, and any related journals, perhaps ? It would be a big help to me. Thanks again for your time :)

  • How to validate a translated questionnaire?

    Any method to validate a translated questionnaire? Since I got a very high cronbach alpha of my translated questionnaire, can i assume that the validity of the questionnaire is high also? Thanks for helping!!

    Paul R. Yarnold · Optimal Data Analysis LLC

    I believe that the following article addresses some aspects of the issue you query: Yarnold, P.R., Bryant, F.B., & Litsas, F. (1989). Type A behavior and psychological androgyny among Greek college students. European Journal of Personality, 3, 249-268.

  • Peng Dong added an answer in DIP:
    How to prepare a TEM sample of organogel

    I have tried to dip copper mash on the surface of the gel as indicated by some articles. But it was to thick to observe my material. how can i cope with that? THX

    Peng Dong · Sun Yat-Sen University

    thank you for your advice, sir. I have tried SEM already. But what I want to observe is lower than the resolution of SEM. Thank you for information of liquid ethane. I will try it someday.

  • Karin R Aubrey added an answer in AAV Vectors:
    How long is AAV vector virulent once injected into an animal?

    I am planning to use AAV vector to express a gene product in the brain in a standard protocol. I am in the process of getting biosafety approval.

    I understand that AAV vector mediated expression lasts a long time, but how long does the vector itself continue to be active/infectious after injection?

    The question is related to safety approval, essentially:

    How long after AAV vector injection can the tissue be treated like wild type tissue with no infection risk? 

    I found this article: Comp Med. Oct 2012; 62(5): 361–37 which suggest a about a week but have not found it easy to find corroborating evidence.

    Thanks for your help

    Karin R Aubrey · University of Sydney

    Thanks for your response John, that helps me a lot. 6 years is a long time. I looked a little further, and found an indication in brain injected tissue that intact vector persists there too for at least 1 month. This report suggested the intact vector was not still active as transfection of nearby tissue did not occur after destroying the transfected cells….

    I will be careful with my terminology! 

  • Tahani k Alshammari added an answer in Interneurons:
    Does anyone have a good marker for hilar interneurons in the hippocampus?

    I am looking for a good antibody to label hilar interneurons in the hippocampus.  I  have tried several antibodies against GABA and GAD from millipore but did not get good signals. Can someone recommend some antibodies that work well?  Thank you.

    Tahani k Alshammari · University of Texas Medical Branch at Galveston

    I use  GAD67 Millipore (1:500) after permeabilizing with tritron 0.3% I use 10%  normal goat serum as blocking  agent for  30 min and it works perfectly.

  • Ahmed Ali added an answer in Species Specificity:

    I have a case of Rabdomyosarcoma (RMS) in a neonatal goat. I would like to do a confirmatory diagnosis using immunohistochemistry (IHC). My question is, whether IHT is species specific?. Can anybody help me?

    Ahmed Ali · Qassim University

    Dear Dr Mohamedm thank you for your interest,

    A neonatal kid displayed a congenital, spherical, subcutaneous mass at the lateral side of the neck. Histopathology showed a highly cellular mass consisting of tumor cells at the myotube stage of muscle development. The tumor cell were mostly tube shaped, the cytoplasm was lucid; the nuclei were elongated and centrally aligned within the tubes. These tumor cells were arranged in parallel as bundles of fibers. Now, I need a confirmation of my first suggestion using the Immunohistochemistry. The question, could I use the commercial AB of human origin for RMS or should use specific one for goats? 

  • Dinah Wang asked a question in Autonomy:
    Seeking for cross-cultural partners woking on the study of Teachers' autonomy support

    I am working on the exploration of a model of teacher's autonomy support of English Learning in Chinese Context. The theoretical framework comes from Deci and Ryan's(SDT) Self-determined Theory. My proposal has been recommended to apply for the provincial grant. I am also looking for the parterners across culturally intending to make comparision study of the differentiated models of teacher's autonomy support in Foreign language learning, where the authority of teachers is more overwhelming. 

    If you are working on this, or your school is in other countries other than China, western countries valuing individualism would be the best, welcome to contact me!

  • Tushar Jagtap asked a question in Hadoop:
    Big Data Project Ideas


    I am master's student. Can anyone suggest me a big data project for a graduate level course.

    Tags: +MapReduce +Hadoop +Predictive Analysis +Networking +Distributed Computing

  • Tareg Mohammed added an answer in Immunology:
    Has anyone managed to successfully lower the number of beads for luminex detection of cytokines?
    After seeing how little of the sample is consumed to acquire the desired number of beads, I thought we may be able to stretch the kit by lowering the number of beads per sample. Hopefully this wouldn't augment the results. I was wondering if anyone had stretched their Miliplex kit.
    Tareg Mohammed · Tohoku University

    So far I have been preapring beads at a density of 200beads/ul and then adding 25ul per well to get 5000 beads (200beads/ul*25ul) per well. I have not tried it yet but I feel this bead number can be very well lowered to as low as 2500 beads per well, i.e., to use either 50beads/ul and then add 50ul per well or use 100beads/ul and then add 25ul per well.

  • Tan Wang added an answer in Optics:
    Can anyone comment on cutting wave plates from birefringent bulk crystals?
    The attached figure (taken from Optics\E. Hecht) shows a calcite bulk crystal in a cleavage form with a wave plate cut parallel to the optic axis.
    From the symmetry of the index ellipsoid there are many ways to cut such a plate from the bulk material - take the plate shown in the figure and rotate it around the optic axis and you also get a plate with identical optical properties. My question is whether there's a preferable way to cut this wave plate with respect to the bulk material. In other words - if two crystal experts are asked to cut this plate, will they both cut it the same way? Or will they'll each make an arbitrary decision of the exact orientation based on the dimensions of the bulk material and the requested wave plate's dimensions?
    I would also appreciate if you can refer me to books/articles regarding how to define correctly crystal parameters (such as optic axis orientation, cutting angles, etc.) for crystal manufacturers.

    Thank you.
    Tan Wang · Beijing Institute Of Technology

    Do you have the full-text or title of the artical. It a pleasure for me to get it from you. 


  • W. A. W. Razali added an answer in Nanophotonics:
    Why I cannot get Alumina particle in nanosize scale using ball milling method?
    Several milling sessions using 5mm, 1mm and 0.2 mm grinding ball were carried out to produce alumina nanoparticle while water was used as a surfactant. Most of the milled powder cannot achieved nanosize scale and tend to agglomerate/stick on grinding jar. Charge ratio has been adjusted from 5 to 100 but still unsuccessful. Can anyone suggest a solution?
    W. A. W. Razali · Macquarie University

    Dear all,

    I have figure out that the ball milling belt for the bowl was broken.

    so annoying..

  • James F Peters added an answer in Mathematics:
    Are there mathematicians, scientists or philosophers whose work you view as influencing historical outcomes in a minor or in a major significant way?
    Do you think that the interaction between such scholars has led to the success of their work in making an impact?

    Scholars such as Euclid (geometry), Newton (science), Plato (philosophy) have
    been very influential in shaping the way we see the world. For example, Euclid’s
    Elements written in Alexandria around 300 B.C. became a standard work in geometry. It is one of the most widely read, translated and commented on work in European history. It was translated into Arabic around 800 A.D., into Chinese in 17th century and into Sanskit in the 18th century. The first english version of Euclid’s Elements was Sir Henry Billingsley’s translation published in 1570. Euclidean geometry has been enormously influential in shaping our view of the world. For more about this, see

    Plato, 428-348 B.C., descendent from kings of Athens and Messenia, student of Socrates, teacher of Aristotle, founded the Academy of Athens, one of the institutions of higher learning in the Western world. He wrote about justice, beauty, equality, political philosophy, theology, cosmology, epistemology and the philosophy of language. For more about this, see
    A central notion in Plato’s philosophy is the theory of forms. The only true being is founded upon the forms, the eternal, unchangeable, perfect types, of which particular objects of sense are imperfect copies. This theory has been enormously influential in science and mathematics. For more
    about this, see

    Isaac Newton, 1643-1727, son of a farmer, Professor at Cambridge University, taught optics, introduced a theory of colours of light and theory of gravitation, published his Mathematical Principles of Natural Philosophy, 1687, introducing infinitesimal calculus, co-discovered (with Leibniz). During his study of optics, Newton investigated the refraction of light, demonstrating that the multi-coloured speturm produced by prism (see attached image) could be recomposed into white light by a lens and a second prism. He showed that colour is the result of objects interacting with already-coloured light rather than objects generating the colour themselves. He designed the first reflecting telescope, demonstrating his telescope to the Royal Society in 1671.
    James F Peters · University of Manitoba

    Dear @Ljubomir and @Behrouz,

    Omar Khayyam's life and work is very interesting.    Obviously, Khayyam had a huge impact on geometry, algebra, and cooperation between mathematicians and artisans.

    In addition, Omar Khayyam had considerable talent as a poet and philosopher.

  • What tools are available for ANN modelling?

    I am currently using Matlab Neural Network Toolbox and would be interested are there some alternatives available. Which tool do you prefer using in research and which to use in lectures? 

  • Max Stanley Chartrand added an answer in Medicine:
    Does the responsibility of researchers end with the scientific publication of their findings?
    Or should he or she also ensure that these findings find a way to a) non-scientific public and b) the implementing authorities / institutions (a practical reference provided)? I have made it my habit to any scientific contribution to compose another layman's contribution and to publish in order to create the possibility of practical implementation. All non-academic partners are extremely grateful for it. Without access to databases they would probably know nothing about these results and findings. Other ways to make research applicable?
    Max Stanley Chartrand · Northcentral University

    Good point, Frederic. Better than a sharp stick in the eye, why not try VisioPlex by Progressive Labs. If you don't have it in stock, call my office at 520-509-6380 and get a bottle of it, taken (2) in am and (2) in pm (the manufacturer recommends double that dose, but our patients have done fine with the lesser dose). Add MCHC (1) to that daily and I think you will see significant or at the least measurable recovery from wet macular degeneration and diabetic retinopathy. I had the same from 20 years of diabetes and completely receoverd doing this. I am posting this on open forum in case another individual would like to try it. It is far better than anything we have seen to-date. It is advanced homeopathic with actual eye cells in its formulae, releases interically if taken on an empty stomach. Just a suggestion since your only other option is one for the walking dead not the thriving and living.  

  • Mingda Wang asked a question in Quantitative Analysis:
    What's the differences between qualitative and quantitative reconstruction in Paleoclimate research?

    In the study of paleoclimate field, the reconstructions of climate from different archives tend to quantitative analysis. What's the advantage of this? Some paper says it can verify the modelling result, such as GCM. Others say it could offer the boundary parameters? What's your opinion for this discussion? Waiting for your reply, especially for the modelling researches? Thanks a lot.

  • Eric Schniter added an answer in Sociology:
    What is the etymology of the expression/phrase "gender smart"?
    Where did it start? In what context? What was it's first/original definition initially?
    Eric Schniter · Chapman University

    Can anyone provide a definition of the term as used in either the Gray text or the Sanders text? My curiosity was piqued now that I saw this thread, but I still dont know what it is.

  • Has the global solution of Navier-Stokes equations been found?

    The global solution of Navier-Stokes equations is one of the biggest mysteries in theoretical physics, and it belongs to list of Millenium problems by Clay Institute.

    But in a recent paper, Dr. Algirdas Maknickas provides a solution to Navier-Stokes equations by transforming these equations into parabolic differential equations, and then to Helmholtz equation. The solution is in the form of sinusoidal wave. See http://vixra.org/abs/1311.0164

    So, do you think that the global solution of Navier-Stokes equations has been found? Your comments are welcome.

    Victor Christianto · University of New Mexico

    @Michael. Thanks, yes 3D N-S problem is much more difficult. Best wishes

  • Does anyone have access to a trust game program file which can be run on ztree?
    I am currently trying to design a variation of the original experiment,but have not been able to find a standard trust game file.
    Eric Schniter · Chapman University

    What is "the original experiment" you refer to? Berg et al was not run on Z-tree.
    Berg, J., Dickhaut, J., & McCabe, K. (1995). Trust, reciprocity, and social history. Games and economic behavior, 10(1), 122-142

  • Robin Spivey added an answer in Theoretical Physics:
    Could time dilation prevent the formation of black holes?
    As we get close in time to the formation of an event horizon, then in the vicinity of the location where that event horizon will form in the future, time dilation becomes very large. The formation of the event horizon must depend on continued entry of material from beyond the radius where the event horizon will form, otherwise it would have already formed. A tiny differential instant before it forms time dilation approaches infinity.

    Of course in the proper time of an observer at that location, there is no time dilation and the black hole forms. But has anyone considered that in the reference frame of a more distant observer in the normal universe there may be no event horizon ever really existing in that observer's reference frame?
    Robin Spivey · Bangor University

    @James Arnold, have you considered the possibility that the time dilation has no local effects? This is why there can be local "acceleration" and non-local "deceleration".

  • Can anyone help me with the protocol regarding the preparation of gelatin methacrylate???

    I have been trying to modify the gelatin by adding the methacrylate group to it using Methacrylic anhydride (94%, Sigma-Aldrich). 

    I followed the given protocol, as shown in many sources of literature. 

    Step 1: made 10% gelatin type A solution at 60 degree C

    Step 2: added 10% (v/v) methacrylic anhydride (94%) into the gelatin solution at the rate of 0.5ml/min and let the reaction continue for next 2 hours.

    After this i am getting a very thick resultant white color solution. Is the direction right???

    What should I do further to get purified version of gelatin methacrylate.???

    Benjamin Fairbanks · The Commonwealth Scientific and Industrial Research Organisation

    The acrylate would be more reactive and more prone to crosslinking than the methacrylate.  There are other ways to make gelMA.  You can use glycidyl methacrylate or use methacrylic acid with EDC and NHS.



  • How may I present the activity of this enzyme?

    I want to compare the absorbance of different stress treatment in explants, for evaluate ppo, how may i present the activity of this enzyme? If i present the absorbance, is correct?

    Ivan Luciano Pequeño-Granado · Autonomous University of Nuevo León

    Thanks guys for yours answers

  • Dinah Wang added an answer in Nursing Journals:
    Is anyone interested in doing a research in self-directed learning or independent learning of first year-college or K12 students?

    I am looking for 2 other researchers from other countries who are interested to do a research on self-directed learning (SDL) of K12 or first year college students. I have read the literature on SDL of students and nursing students; quite a lot of the literature was from nursing journals, and it’s not surprising because nurses surely need to be very self directed and independent learners.  My students come in after 11 years of school but they are very dependent, and need to be transformed to become SD learners.

    If you have other resources, it would be useful too. Please get in touch on RG platform.

    Dinah Wang · Wuhan University of Technology

    Dear Miranda,

    I am working on the exploration of a model of teacher's autonomy support of English Learning in Chinese Context. The theoretical framework comes from Deci and Ryan's(SDT) Self-determined Theory. My proposal has been recommended to apply for the provincial grant. I am also looking for the parterners across culturally intending to make comparision study of the differentiated models of teacher's autonomy support in Foreign language learning, where the authority of teachers is more overwhelming. Your interest of cross-cultural study fits in my research. I'd like to expect more details with you.

  • Semiconductor laser flashes but there is no continuous wave radiation. What's going on?

    I have worked with quite a few laser diodes, but this one is proving rather mysterious.  It is a non-coated LD. There is no lasing at the specified threshold current or operating current, just fluorescence.  However, there is a flash of, what looks to be, laser light when the current cable is simply connected to the diode with the expected mode shape (but not when using the on/off switch of the current supply).  There seems to be a momentary surge of current that creates the laser flash — nothing new, but it does suggest that the diode is not completely dead. The obvious thing to do is just keep ramping up the current until  there is complete failure (or lasing), which I will most likely do.  I am curious to know if anyone has seen this kind of behaviour before. Maybe something is happening in the chip that prevents a stable cavity.   The spec sheets weren't dated, so I don't know how old the chips are (the light is red, but this is likely to be inconsequential). 

  • Dian Brindar asked a question in Down Syndrome:
    Down's Syndrome

    I need a full thesis paper about cytogenetic study on down's syndrome!!!!

  • It is possible to achieve high storage and long life cycle by using metal with graphitic oxide nanoparticle for supercapacitor electrode material?

    I want to know whether it is possible to achieve high energy and long life cycle for supercapacitor electrode material by using metal with graphitic oxide nanoparticle.

    Sridhar Vadahanambi · Global Core Research Center for Ships and Offshore Plants,

    Yes its possible, but with reduced graphene oxide+ metal oxide composites... literally hundreds of papers on reduced graphene/metal oxides based asymmetric super-capacitors. 

  • Mingda Wang asked a question in Wind:
    Can we call monsoon system an atmospheric circulation?

    It puzzled me for a period whether monsoon system is what we call atmospheric circulation or not. Unlike westerlies or trade winds, the planetary wind belt existed in different latitude, monsoon is mainly driven by thermal difference between land and ocean. Hence the monsoon is always related to the word"advance" or "retreat", not"circulation". I really wanna hear your voice. Thanks.

  • Richard M Lynch added an answer in Morphology:
    Why is it that in any single lead are QRS complexes not always the same height even though they are the same morphologically?

    For example: I have an ECG if front of me now.

    The QRS complexes in lead II are morphologically the same but they are not all the same height, varying from 6-10mm. This height differences is present in all 12 leads. Can anyone explain this for me and put an old man out of his misery?

    Richard M Lynch · Health Service Executive

    Thank you to everyone who has submitted an answer

    Didn't know I could upload pictures

    The ones attached are a good example of what my question relates to. Not all the QRS complexes in some leads are the same height as the other QRS complexes in the same lead. Can anyone explain?  Richard

  • Albert Bai asked a question in Flow:
    Choosing a water pump

    I need a water pump that has a low flow rate, the maximum rate should not exceed 500mL/min, and I can change and control the flow rate. Do you guys have any recommendations which is around $1,000? Thanks.