Biotechnology

The ability to accurately measure mechanical properties in the fields of Life Science has recently become an important aspect of many current studies. In some cases, understanding the mechanical properties of soft biological surfaces have helped uncover the mechanical effects of diseases. Understanding mechanical properties provides a context for identifying the local mechanical behavior linked to specific changes. It is also critical in the development of artificial bio-materials. App Note: http://www.nanovea.com/Application%20Notes/nanoindentation-tissue.pdf

I am trying to purify a heterologously-produced virus-like particle, and PEG precipitation (or ammonium sulfate precipitation) would really help. I have done a couple of trials but they didn't seem to work. Which variables are best to play with? Type of PEG? PEG concentration? Salt concentration? Speed of centrifugation? Duration of centrifugation? Any advice on optimisation would be welcome.

Microbes often form consortia performing material processing and cycling in the environment. Cooperation and interaction occur within those consortia. We can use microbial consortia to do work like degrading pollutants, producing proteins or chemicals. Is is possible to regulate bacterial interactions among certain bacteria populations? e.g., manipulating their quorum sensing systems?

I got the results seen attached below before (up) and after (down) treating cells with plant extract. Can somebody help me understand why the treated cells have spaces within the monolayer. Does it suggest decrease in proliferation, death or?

I wonder why some labs are very productive and doing good science while others not. Do good labs have some patterns or structures that others can follow? To run a good research lab, what should we pay attention to? the students, post docs, advisers, technicians, collaboration, projects, grants, ideas and proposals... ?

The cut bands of DGGE gel are going to be subjected to PCR. These cut bands are in sterile water. After spin downing, the supernatant will be used for PCR. Currently these samples are stored at 4oC.

I use to prepare my medium a weight of sucrose per Liter, but I don't understand when talk me about percent (%) , for example: sacarose 2% w/v. Can you explain me?

Can anyone tell me whether 10ng template sufficient for transcription reaction

I read this expression in one article, but I don't understans that.

When you are talking about frequences, what this mean?

If we use citrate buffer(sodium citrate) it shows more absorbance

I'm trying to modify oligonucleotides (20-30 base) using sugars and other different molecules. But I have difficulty in separation and purification of reaction products due to low amount (low concentration) of sample. Could you suggest me a way to purify these compounds except HPLC and LC-MS?. Our LC-MS detection limit is up to 2000 and my product's molecular weight is approximately 4000. Thanks in advance for your interest

PCR assays failed even samples were diluted. Scientist suspected it was Pluronic in samples. Does someone know the max conc. allowed Pluronic in PCR reaction?

Some alkali would help, but I suspect I would get a large amount of breakdown in the xylan structure if I increase the alkali concentration too high. I would like to dissolve it to at least a 10% or higher concentration.

I'm looking to create a database of cell lines I use and their characterisitcs i.e pathways active. I also want to add experimental findings i.e effects of drugs on the cell lines. Excel won't do. Ideally it needs to be a database that can be searched and added to easily. Does anyone know of any software that could be useful so that I can easily look for a cell line and see all the information I have gathered on it?

What is the meaning of a negative value in response surface methodology?

I looked up many protocols for freezing bacteria, but the concentration of glycerol varies from 20% to 80%. How should I choose? Is it v/v or w/w? One of the protocols mentioned spinning the cell first and then adding fresh medium and 20% glycerol. If liquid nitrogen is unavailable, is it ok to put the mixture from RT into a fridge at -80C? Sometimes cell pellets formed after freezing, how can I avoid pellet formation without using liquid nitrogen? ----- updated on April 9 I think I may fine some causes to the previous failure of my recombinant expression E.coli. Some colleagues suggest that there are different treatment for different types bacteria. Sergii Pochekailov: as for a high-expression-rate strain, it is better to use freshly transformed bacteria, or the expression would drop dramatically. Jen-Ning Tsai: in the case of the BL21 and its derivatives (commonly used in recombinant protein expression), the manufacturers suggest a lower glycerol concentration for storage of the cells, since glycerol concentrations (> 10%) may lead to plasmid instability. ---------- updated on June 7 Ignasi Roca mentioned another interesting method for bacteria storage. Using skimmed milk instead of glycerol. Since scraping the vials without completely thawing the sample required a very fast operation, he change into 20% skimmed milk. He get longer survival times, besides, thawing is not an issue anymore! I f you are interested, the protocol is detailed in his answer and attatched paper.

It means if two ethnic groups have one ward difference then what will be our explanation for them.

Any available software to draw pathways and chemical structures?

I look for a software to draw a circular viral genome, indicating the beginning and end of ORFs, which is a way to show the organization of a genome. Sending attached a photo of a genome, which would like to use as an example.

Protein estimation

In our lab we got good results on inhibitory activity of some of plant extracts on fungus by in-vitro study and I would like to continue the study in-vivo using rats. We tried many methods but we couldn't standardize the method . Can anyone share their experience and help me out further?

I would like to know a suitable method to check the intestinal absorption of some lipidic components such as fatty acids. I have read about the Caco-2 cell assay. Could you tell me your experience with this procedure, particularly the advantages and disadvantages that can be expected? Is there any other alternative?

I am looking for concentration of plant membrane proteins. Please suggest anyefficient and advanced method to detect them.

I think my protein could be a dimeric protein. What do I need to do to confirm this fact?

What is the effect of combining and separating in downstream analysis?

can someone suggest simple experiments to prove that the Protein-protein interaction is not DNA-dependent. I will not use the IP fraction for any assays. It will only be used to identify interacting partners/ western blot.

The type strain is CMU-PLA07T (=JCM 16380T, = BCC 38279T). Here CMU-PLA07 is Chiang Mai University and strain no, What is the meaning of T? What is the meaning of =JCM 16380T, = BCC 38279T? Can any one tell me?

If a (purified) protein of an unknown gene interacts with an antibody, is it possible to get the nucleotide sequence without protein sequencing? Does any body have any explanation for this ?

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