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

  • Puriya Gharavi-Kouchebagh added an answer in Salt Stress:
    How can I give salt stress to Arabidopsis seeds in Ms medium?

    this is a part of my experiment in which i want to know the response of Arabidopsis to different concentration of salt stress using MS medium, but i am confused that forexample i am using 50mM salt stress means add 50mM saline solution to media or make the final concentration to 50mM including MS Media. please guide. thanks in advance

    Puriya Gharavi-Kouchebagh · University of Tabriz

    As Radwa said this site is good


  • Qi Feng added an answer in Cell Imaging:
    Which kind of cell line that I can choose in cell -imaging (for caspase-4 activated by TLR-4 ligand)?

    I want to do the cell imaging of caspase-4 that activated by the TLR-4 ligand. However, I do not know , which kind of cell line that I should choose. I hope someone can tell me . Thanks very much.

    Qi Feng · Osaka University

    Dear Aaro,

    Thanks for your reply. Your suggestion is very good. I know THP-1 well. In my study, I want to use FRET biosensor to check the activation of caspase-4. Firstly, I need to transfect the FRET DNA plasmid into THP-1, then by PMA differentiated into Macrophage and stimulate by the TLR-4 ligands. However, I check some references, a lot of researcher said that THP-1 is hard to transfection and the viability after transfection and PMA induce is very low. So, I am confused. I know THP-1 is the best candidate cell line, however, its poor transfection ability led me disappointed. I sincerely want to you if you have some experience in this field, I am looking forward to your reply. Thanks again.

  • Dmitry Guschin added an answer in Poly I-C:
    Does anyone have any experience with preparing poly(I : C)-coated agarose beads from poly(C)-coated beads by incubating them with poly(I)?

    Hi everyone, 

    I just bought Polycytidylic acid–Agarose and Polyinosinic from Sigma, I am wondering how much buffer I should add to resuspend the Polycytidylic acid–Agarose beads in order to prepared the Poly(I : C)-coated agarose beads.

    Can anyone help me?


    Dmitry Guschin · Allel, Center for Innovative Biotechnology, Moscow

    It might be not that simple, depending on the length of dC and dI. If they are long - 1kb or so than - forming good ds(dI:dC) will be tricky. Hybridizing strands by mixing in normal salt and room T will likely lead to a lot of bulges. You could use minimal amount of buffer, say just enough to make a handable slurry, and add dC up to 100ng/ml - 1mg/ml range and heat your mix up to say 50 C, incubate for 30-60min and -slowly cool down. I would use something like PBS as incubation buffer. You could measure how much of your dI left bound by measuring  the dI conc. before and after the incubation with dC agarose. This is just a thoughts, I haven't done something like that. :)

  • Mahmoud Mazarji added an answer in Leachate:
    What types of chemical materials are better to use in order to simulate artificial leachate with COD around 60,000 mg/L?

    Dear all,

    I intend to make 1 m3 of artificial leachate by COD around 60,000 mg/L. I am looking for the materials which are available in commercial form,Thank you in advance.


    Mahmoud Mazarji · University of Tehran

    Dear Ms. Gupta, My aim is to provide artificial leachate, hence I can not use other collected samples from elsewhere. 

    As suggested by Mr. Semrany, acetic acid or a simple sugar (glucose) can help me to achieve the desired COD values. 

  • Ariel Vina-Rodriguez added an answer in PCR Assay:
    Do you know what happened in my real time PCR?

    I use the amplicon to be a positive control for a multiplex taqman realtime PCR assay. So I designed the amplicon and checked the sequence of amplicon, its sequence is OK for the primers and probes.

    But when I realtime PCR, the signals are Ok on gDNA but not ok on the amplicons (~1000 bp). I don't know why.

    Ariel Vina-Rodriguez · Friedrich Loeffler Institute

    Ok. The first question is now clear. Only two pair. But still only one target molecule with two site. In the gDNA are the PCR targets also near (one PCR zone continuos to the other)? Or,  ...do the gDNA have only one of them?

    Are the two sites near or in different zones of the "amplicon"? How do you obtain the amplicon? Synthesis? Is a plasmid? Lineal or circular? Maybe you have an scheme or some link to expain it easier...

    And still: Did you test just one primer pair? Are you sure the concentration of the control is OK? Too hight or too low concentration of the amplicom can be the problem.

  • Paolo Scarpelli added an answer in DNAse:
    Any experience with On-column Turbo DNase treatment during RNA isolation?

    Does anyone have experience with using Turbo DNase [Ambion] implemented in a column RNA isolation? For some Dnases it is especially noticed by the manufacturer that it is tested for on-column use, but not for Turbo DNase.

    kind regards.

    Paolo Scarpelli · Università degli Studi di Perugia

    DNase I digestion works better in a in-solution reaction, Turbo DNase is also designed for a in-solution digestion. I guess is better to elute RNAs and perform the digestion later. 

  • Patrice Showers Corneli added an answer in Gene Sequencing:
    Is distance, parsimony or likehood analysis most suited for Interspecies relationship analysis?

    I will working with mithocondrial gene (CO1) and ssurRNA partial gene for confirm marine parasites (Dicyemids) relationship. Does the gene sequences would sufficient to provide relationship information for Distance, parsimony, and likehood analysis? and which one is the best for describe my goal?  

    Patrice Showers Corneli · University of Utah

    You are so welcome. It was a pleasure to do.

  • Azes Giwa added an answer in Legislation:
    Does anyone know a critical assessment of the German Constitutional Court 2015 ruling on headscarves (1 BvR 471/10 and 1 BvR 1181/109) in English?

    The 2015 ruling condemning the NRW legislation on headscarves worn by teachers seems again focused on religion, though this time on discrimination instead of religious freedom. I wonder whether there is a debate on the ethnic and gender discrimination involved here. I am aware of some German publications in the general press, partly by women who criticise the ruling as supporting patriarchal rule, but have not seen any English case note yet, looking on this other aspect. 

    Azes Giwa · London South Bank University

    The one  I am aware of his the one you have found already attached by Barry Turner 

  • David Carvajal added an answer in Game Analysis:
    Can anybody direct me to research, of any kind, that references the game TETRIS?

    I am looking at binomial probabilities in time series data, both stochastic and discrete information theories. The Tetris game is a funny and coincidental descriptive model for the project. I am looking for a way to include it more fully, and I wonder if other people have done so.

    David Carvajal · Complutense University of Madrid

    As Melissa said about mental rotation and other spatial skills training, as currently I'm researching, you can find some info in these papers, directly from my Mendeley library:

    Enhancing visuospatial performance through video game training to increase learning in visuospatial science domains.


    Video games and spatial cognition.


    Enhancing cognition with video games: a multiple game training study.


    Brain training game boosts executive functions, working memory and processing speed in the young adults: a randomized controlled trial.


    Serious Games : An Overview


    The power of play: The effects of portal 2 and lumosity on cognitive and noncognitive skills


    Enumeration versus multiple object tracking: the case of action video game players.




  • Mohamed Elghoul asked a question in Athletes:
    Can anyone tell me what is the importance of measuring brain activity by EGG for athletes?

    we know the professional players have alot of ability in skills fitness etc so that's reflect on the brain activity ... what is the real facts and the important from using EEG and measuring the activity of brain and what is the benefit from that?

  • Ulrike Kammann added an answer in Comet Assay:
    Comet assay with cells on the edge only

    Hello, I am running Fpg linked comet assay and I found that all of my cells on the edge of the gels with a very narrow range, and no cell can be seen in most of the gel. Which step may lead to this situation?

    Ulrike Kammann · Thünen Institute

    It could be the case that the cells are at the bottom of the tube after mixing with the agarose or sink down in the pipette tip while transfering. A wrong concentration of agarose, wrong temperature or ineffective mixing are possible causes.

  • Irene Fernandez added an answer in Soil Respiration:
    How to estimate soil respiration in the field?

    Any soil scientist or soil microbiologist

    Irene Fernandez · Consejo Superior de Investigaciones Cientificas (Spanish National Research Council)

    The use of a portable  infrared gas analysers (EGM4) with a closed dynamic soil respiration chamber (SRC1) from "PP Systems" allowed us to obtain "in situ" measurements of soil CO2 effluxes in pine forest ecosystems, where soil respiration in the field was seasonally monitored in order to determine the intra-annual variations of the C effluxes through the soil-atmosphere interphase.  For more details, you can have a look at "Results" or the "Material and Methods" sections of the attached papers (Fernandez et al. 2012, Can J For Res 42, 1953-1964; Fernandez et al. 2012, Eur J For Res 131, 1681-1693; Fernandez el al. 2010, Forestry Ideas 16(2), 250-257).

  • Chris James Headleand asked a question in Shopping mall:
    Anatomy of a Crowd - Are there different classes of group behaviour?

    Can anyone point me towards a paper that details various different types of group? I'm looking for something that details the behaviours of different classes of crowd. For example, is there an anthropological or sociological difference between the crowd at a stadium, or a crowd in a shopping mall? Is there a taxonomical classification? 

  • Muhammed Fasil asked a question in Simulink:
    SVPWM converter has a delay. How can i implement it through simulink block?

    "The output voltage of the converter is assumed to follow voltage reference signal with an average time delay equals to half of a switching cycle, due to VSC switches, Y(s)=1/1+TaS where Ta= Tswitch/2"

    If il use a transfer function block with above values can i achieve that time delay?

    What is "Transport delay" block for?

  • Baffour Ohene Agyekum asked a question in Conversion:

    With particular reference to conversion of colleges of education to tertiary institutions.

  • Divaker Choubey added an answer in Ornithine:
    How do I induce fast growth in LUHMES cells?

    cells have been revived but growth is not that good.

    Cells are grown in ATCC medium. And plates are also coated with Poly L ornithine.

    Divaker Choubey · University of Cincinnati

    To increase cell survival and support cell proliferation upon revival of cells, several factors need to be optimum, including the growth factor and cell density. Therefore, if cells are not proliferating, these two factors need to be checked.

  • Akshay Srinivas Bhat added an answer in Return of Investment:
    Can anyone comment on relevance of Shubh-labha (Goodness-benefit) in Indian business system?

    Till date we have been discussing Net profit and (Return on Investment) ROI. Why don’t we talk about “Shubh-Labh” (Goodness & benefit)? This implies that individual and corporate actions should be driven by the criterion of the overall benefit of the society. India ought to spread the relevance of Indian ethos, which laid down our milestones of success. Out of many ethos, ethical profits or “shubha labha” is one of the important notions and has been used by Indians from thousands of years. More research on this topic is invited.

    Akshay Srinivas Bhat · XLRI School of Business & Human Resources

    Well taking forth, it is perhaps the Indian business way of looking at CSR, Sustainable Competitive Advantage and Triple Bottom Line reporting.

  • Balewgize Amare Zeru asked a question in Boiling Heat Transfer:
    What are the capacity range of applications of flow boiling heat transfer?

    Flow boiling has an advantage in higher heat flux application ideal for miniature applications. What are the limitations that govern the application of flow boiling heat transfer over sensible cooling with respect to size of the device? Are there correlative figures available for selection appropriate means of cooling method?

  • Paolo Scarpelli added an answer in Primer:
    Why are my positive controls and my test samples not producing the same band sizes when I used the same primers for amplification?

    I am amplifying the DHFR gene through a nested approach using the positive control and primers M1/M5 set sent to me by BEI resources. My positive control band is about 650bp which is the size expected, but my samples are showing bands of about 1000. What is going wrong?

    Paolo Scarpelli · Università degli Studi di Perugia

    On thing you could do is pick up the bands, purify the bands and send both for a Sanger sequencing assay. The sequencing never lie on what you amplified if it is only an unspecific band or better a new (or even known) length polymorphism. 

  • Jacques Gleyse added an answer in Sporting Events:
    Has anyone had any experience on measuring the economic impact of major sporting events on a region?

    I am co-authoring a paper on this topic and would like examples of IO models used. 

    Jacques Gleyse · Université Montpellier

    I've forgotten that I've been writing something in the Huffington Post about Brazil. The paper is named : La Coupe est pleine.  http://www.huffingtonpost.fr/jacques-gleyse/mondial-2014-au-bresil-la_b_5429832.html

  • Shian-Loong Bernard Lew added an answer in Discovery:
    Of what use is serendipitous discovery to problem solving?

    It would seem that breakthroughs in the past has often originated from what Freud referred to as parapraxes. Some have attributed this to the power of the intuition over rational thought in creativity. What are your views?


    Shian-Loong Bernard Lew · Taylor's University

    Dear Christopher,

    Reminds me of sensitivity to initial conditions and path dependence.Far from being an abstract framework, Chaos and complexity finds applications even in the psychology of problem-solving. The paradox is that "right footing" is critical and yet problem solving requires a "leap of faith".

  • Ashish Kumar added an answer in Raman Microscopy:
    What information can be extracted from the intensity, FWHM and raman shift of the ZnO Raman spectra ?

    Raman spectroscopy is powerful tool ti investigate the phase and purity of the crystal. But How ?

    What are significant of the intensity, shifting and FWHM and how? 

    Ashish Kumar · Indian Institute of Technology Indore

    Thank you so Much Dr. Hatsuo Ishida to write the answer 

    I have also got one nice article 

    Thank you so much 

  • Sudev Naduvath added an answer in Yoga:
    How Yoga affect health?can it deals with some diseases?

    I collect Data about yoga if some one has informations about it

    Sudev Naduvath · Vidya Academy of Science & Technology

    Yoga is a systematics and traditional physical exercises. It should not be considered as a remedy for all types of diseases. Yoga has a lot of benefits as mentioned in the previous answers. It has the ability control many unhealthy physical conditions of our body.  Like any physical exercises, yoga also have some adverse effects if practised in a wrong manner. Here are some more links explaining merits and demerits of yoga.

  • Purvi Kikani added an answer in Atmospheric Pressure:
    Which gas feeding mechanism is better for atmospheric pressure PECVD experiments?

    We want to deposit SiOx film from HMDSO and Oxygen mixture at atmospheric pressure by PECVD method. What will be the difference in process / film properties if precursor is feed via bubbler type arrangement or aerosol generator ? when bubbler type feeding is better and when aerosol type ?

    Purvi Kikani · Institute for Plasma Research

    Thank you mam, we will use 20 - 40 KHz DBD plasma. Also at low pressure I have deposited films with vapor state and liquid state of precursor introduction. At low pressure we made plasma with 13.56 MHz parallel plate. We found big dimensional clusters in the case of liquid precursor introduction and very small dimensional particle clusters with vapor case.

    I want to understand this mechanism. Also why powder formation will take place with only vapor state of precursor and why not with liquid state of precursor ?

  • Syed Hadi Hasan added an answer in Pollution:
    What are the applications of biosorbents in full scale systems?

    Would be great to have a summary of systems, where polluted waters (not only wastewater) are treated using biosorbents.

    Have you heard of such systems?

    Syed Hadi Hasan · Indian Institute of Technology (Banaras Hindu University) Varanasi

    There are number of publications ,review and books where removal of toxic substances have been discussed.One of my review" Cellulosic substrates for removal of pollutants from aqueous systems: A review. Metals.Martin A. Hubbe, Syed Hadi Hasan, Joel J. Ducoste, Bioresources (2011)" has given every information related to biosorption.

  • Akshay Srinivas Bhat added an answer in UCINET:
    Softwares for drawing firm networks ?

    Hi !

    I am mapping the evolution of a companies joint ventures over a longitudinal passage of time. 

    May I solicit some suggestions as to how to make this possible, the graph has to be dynamic. UCINET and Net logo are static in nature. I can try this on google motion charts as well but wanted to know whether there are other softwares as well.

    Cordial Regards,


    Akshay Srinivas Bhat · XLRI School of Business & Human Resources

    Hi Laura !

    No they do not come from a survey, I have bootstrapped data from various sources about a firms networks over the years. 

    Thanks !

  • Utkarsh Kapoor added an answer in Pluripotent Stem Cells:
    How to achieve Induced Pluripotency?

    Can anybody suggest me how to perform and get a perfect induced pluripotent stem cells.

    What are the critical factors to be considered?

    Molecular mechanism?

    Methods and Mediators and their significant?

    I am planning for neurogenesis from iPS it would also be helpful if you guide me for chemical methods for neural differentiation and growth?

    Chemical mediators and optimal dose range etc? 

    Utkarsh Kapoor · Max F. Perutz Laboratories

    Hi Kannan,

    John has explained things very well. In addition, I suggest you to have a look at the Stem Cell Differentiation link at following website:


    This is a very useful website which has compiled different published differentiation protocols for obtaining cell types of all lineages viz. endoderm,ectoderm,mesoderm and extra-embryonic from ES/iPS cells. You can compare the different protocols that people have utilised/developed to generate neurons of different kinds (motor, dopaminergic etc) along with any available gene expression data.

    Good Luck!

  • Neelakant Varma added an answer in SDS-PAGE:
    Can anyone help me, why my SDS-PAGE gel smears like that?

    It especially concerns 9th well. Will diluting my SB sample with water help?

    Neelakant Varma · Gujarat Forensic Sciences University

    A likely explanation is that each time there was a delay between loading the samples and actually running the gel might cause this problem. please go through the link below for troubleshooting 

  • Rajat Pradhan added an answer in Philosophy:
    Does certainty or absolute truth exist?
    Our means of perceiving reality through our senses make us vulnerable to distortions and biases. But with scientific methodologies, can we claim that perception of objective reality is indeed possible? OR objective reality only in the context of known knowledge of the time/period?
    Rajat Pradhan · Utkal University

    Dear Bernd,

    Please take no offence and no offence was meant anyway.

    I respect your experiences and everyone's experiences need to respected as part and parcel of that absolute Truth. I am not camouflaging anything. i am also serious. And I don't also like some imposter putting this question under the pseudonym "Gautama Buddha", though the question itself is a good one.

    I am neither trivializing your thoughts and experiences nor trying to show myself above you or anyone. We are just discussing as fellow RG mates. You are already superior to me in many respects.

    "Buddha, Krishna or Shiva are in the imagination. "--- Alright, But so are all of us also in one another's imagination (nobody has seen anybody). Just as you write on this string and I see and respond about a day or even a week afterwards, similarly also Buddha wrote or spoke thousands of years back and we are responding now. They are not non-existent just as we are not. If they are figments of imagination, so are  we also.

    Best Regads,


  • Muhammad Khan added an answer in Drug Design:
    Can anyone recommend some free downloadable softwares for drug designing?

    i need to know some free downloadable softwres for drug designing?

    Muhammad Khan · Mohammad Ali Jinnah University

    thank you brother