cellgene

Dear All

I have already observed interaction of 2 proteins using co-immunoprecipitation methods from total cell lysates.

I would like to check whether this interaction is direct. Therefore, I decided to use recombinant proteins (one protein with GST tag) and make a GST pull-down. The problem is, we are not very experienced with protein purification so decided to buy the recombinant proteins, which are quite expensive.

Do you have any suggestions on how much protein is enough for such a pull down? I bought 10 micrograms each only. When I check papers they always use 10-50ug for each pulldown, but I am guessing this is only because they purified the protein themselves and used a lot of it. Is it enough to use about 1ug each for an experiment?

Thanks in advance!