silver stain negative results

[Dima Klenchin]

lancle2 at usfca.edu (lesley lancaster) wrote:
:I am staining protein/polyacrylamide gels with bio-rad's silver stain plus.
:when i stain SDS gels, the bands look fine. when i stain native gels, my
:(snail) proteins do not show up, leaving only shadowy white bands in some
:lanes against the deepening background-- i am not entirely convinced that
:these are a result of the protein. my colleague's (insect) proteins appear
:just fine on the same native gel (she uses urea, i use bio-rad's native
:sample buffer). since the proteins show up w/ SDS, i am confused as to
:where the go in Native.... maybe a buffer problem? I hope somebody has some
:experience with this. Thanks, Lesley   

Native gels are a lot trickier to get working adequately,
and even when it's done, their quality and resolution is by
far inferior to that of SDS PAGE. There could be many 
different scenarios (all testable). íy first suspects
in your case would be: 1) your buffer system does not 
resolve most of your proteins, 2) your proteins stick
to the gel and smear without separation. 

To see if it is really silver staining problem, load
more and stain by Coomassie.

        - Dima