no band and fuzzy bands

[waffaa_qm]

hi I have avery big problem which is :
I inject yhe same sample in 12% gel and 6% gel there is band appear in 12% gel in high molecular weight but no band in 6%
and also the band in 12% is faint
also the front line doesn`t appear after destain
I don`t know what is the problem
is it in the cell of electrophoresis or power supply or in the stain or in the gel itself or in the running bufffer or in the loading buffer
please any one reply me my time is waste I repeat this run 4 times and every time give bad result
thanks

[danfive]

What is the size of the protein? Is it glycosylated? Are you using Tris-HCL gels in both cases?
First consider using a gradient gel 8-16% or 10-20%, in my opinion they result in sharper crisper bands. Second monitor the amps on the power supply perhaps the resistance in the electrophoresis is different between your two gel runs. Is your sample a mix of differentl proteins or relatively pure protein i.e. do you expect a lot of bands per lane or just one?

[kmunson779]

Without more details it is impossible to find the problem. If you post your protocol we'll have a better idea what you're trying to do (what kinds of samples, how are you preparing them, are you using the standard Laemelli protocol, how are you staining the gels, etc.)

Posting pictures of the gels would be a good start. Try comparing your gels to the pictures at the SDS-PAGE Hall of Shame, which offers some troubleshooting tips.

Another thing to try is replacing all solutions with brand new, freshly made and see if that clears up the problem: much faster than trying to change each one individually.