Acrylamide-Bisacrylamide ratio - when should it be low/high (Mar/20/2006 )

Hey,

I want to do protein 2D electrophoresis using SDS in the 2nd dimension and I was wondering what kind of acrylamide/bisacrylamide ratio i should use when i cast my gels
Should it be higher for small proteins? And what if you use a whole proteinextract from an animal tissue for example?

Could you help me with this guys? Because I just found out you can order acrylamide fluid in a whole bunch of ratios!

Thx in advance!

Wozzels

for PAGE of proteins, in general, you should use a 37.5:1 ratio of acrylamide:bis.

on a biorad flyer I saw :

ratio 19:1 for DNA gels
ratio 29:1 for resolving gels
ratio 37.5:1 for separating gels.

Usually I use 37.5:1, but when I have small proteins (less than 10 kDa) I make a tris tricine gel with 29:1