In article <3959FE10.EF0D4DC4 at casema.net>, Suzanne Hermeling
<deefsuus at casema.net> wrote:
> I have a question. I am working on protein purification and because I
> have very low protein concentration I use silverstaining to visualize
> the proteins on an SDS-PAGE gel.
>> But here comes the problem:
> One time we have a good pattern of proteins and the other time we have
> only a very dark background without any pattern.
If it is a contamination problem then make sure your glass plates for
electrophoresis are *really* clean (start with a nitric acid wash)
and also make sure your staining box is equally clean.
If you are fixing your gel with acetic acid before staining
make sure you have *throughly* rinsed it with high quality water
before you start to stain.
When making up the staining solution use very high quality water
(we actually use HPLC grade).
If it is a development problem then you have to stand there and
watch the pattern develop and stop it when it is optimal. You
cannot simply time the process as it takes a variable period for
the bands to start to appear and the background will come up soon
Bernard P. Murray, PhD
bpmurray at cgl . ucsf . edu
Department of Cellular & Molecular Pharmacology, UCSF