Home-made SDS-PAGE gels - acrylamide +/- bis? - (Feb/21/2012 )

Just wondering if there is a difference in the acrylamide:bis ratio in the acrylamide solution used to make western gels?

I have been using 40:1 acrylamide-bis solutions but ran out of that. However, I realised that our lab has a stock of solutions with acrylamide alone, 29:1 acrylamide-bis etc. So my question is, how important is bis and what will be the mix changes I have to make to use another composition?

N.B. all solutions are Biorad stuff.

increased percentage of bis will cause more crosslinking. that will reduce the size of the pores and make the gel more restrictive.

if you want consistent results then you should not change your gel formulation.