1
vote
1answer
46 views

What is an effective method for putting on blue rubber butyl stoppers?

They look like this. We have to do a lot of gas sampling and these are really difficult to assemble. I've been scouring the internet for advice but there are none. Do you have experience with ...
2
votes
1answer
67 views

Substitute 25mM dNTPs mix with 10mM dNTPs

I need to make a solution of multiple compounds, one of them is dNTPs. The recipe calls for 20 μl 25 mM dNTPs in a 1250 μL master mix. Unfortunately I do not have it available at that concentration, ...
2
votes
0answers
127 views

What tests can be performed to test the purity and quality of the raw peptide HCG (Human Chorionic Gonadotropin)

What tests could be run to test the purity and type of HCG? We are looking to purchase HCG from China but the purity and quality varies between labs, we are able to receive samples of the raw peptide ...
4
votes
1answer
116 views

How do you store membrane proteins?

We're producing some membrane proteins and they aren't amenable to freeze thaws even when we add glycerol. The proteins are solubilized in detergent above the cmc so they should be in micelle form in ...
5
votes
1answer
382 views

Using ion-exchange chromatography to purify DNA from a cell extract - Is DNA more negatively charged then RNA?

When applying this method we have a glass or plastic column of resin which is positively charged. Then we pour cell extract into the column in order to capture the negatively charged particles which ...
8
votes
2answers
4k views

Why should I degas my gel solution for polyacrylamide gels?

In protocols for polyacrylamide gel electrophoresis (PAGE) I often see instructions to degas the gel solution by putting it under vacuum for 10-15 minutes before polymerizing the gel. I usually ...