Not getting lower molecular weight bands in SDS-PAGE

[writoban]

I am performing SDS-PAGE with mitochondrial fractions. after transfering the protein in nitrocellulose membrane when i'm staining the same with Ponceau's solution, i am getting distinct bands at higher molecular weight region but not getting anything below 35 kD region. i'm approximately loading 25 micro gram of protein. i have confirmed the observation by immunobloting the membrane with higher (VDAC-1) and lower molecular weight (COX-IV) proteins. Could you please help??(12% SDS-PAGE, TRIS-GLYCINE GEL RUNNING BUFFER)

thanking you in anticipation,
Writoban.

[MrMistery]

hmm, just a random thought, but maybe your voltage is too high when you're doing the transfer. the smaller proteins, that move faster, might simply go through the membrane. I have never heard of this happening anywhere though, but then again, I've never heard of a problem similar to yours either