I would try using protein markers (with your smallest at 5kDa), running
the sample in a center lane, and 1/2 to 2/3 the current time you are using
now. I have also heard/read of using a stain that allows the samples to
be seen as the gel runs; however, I can't remember the where.
I hope this helps,
Ryan
Rasmus Wendelbo Nielsen wrote:
> I am currently trying to purify a protein of 5 kDa, but are having
> problems detecting the protein. As it only contains tree tyrosines and
> no tryptophans the A280 is very low. I have tried running 18% SDS-PA
> gels and a 15 to 25% SDS PA gradient-gels, without luck, the protein
> probably diffuses out of the gel during staining.
> So I am looking for other (easy) ways to detect low MW proteins. Any
> ideas would be appreciated!
> I have heard that adding coomassie to the running buffer instead of
> post-staining the gels could be a solution. Anyone got experience with
> that?
> Thanks, Rasmus