problem with sds page - (Jan/11/2008 )

Recently i have got a bit fuzzy and double bands in sds mini gel preparpation for 10 % self casted gels.

I have recently used sds from old stockas new stock was over and requistion for new one takes time.While making the gel loading dye ( with dtt, glycerol, tris etc) this sds caused pH of gel loading dye to change so it wont be blue.So i added NaOH to it.The molecular weights came out fine with this dye.


But protein (crp) bands are a bit fuzzy and sometimes double.(very close spaced)
Is this due to bad sds or improperly shaped combs due to bad polymerization.(i use 200 ul of 0.1 g aps in 1ml)

Have you tried increase SDS to 12-15%? It worked for me.