Protein Gel Problems

[bioc07 at otago.ac.nz]

In article <EBBB34854020458E at LUCY.WELLESLEY.EDU>, MMELAN at LUCY.WELLESLEY.EDU (Melissa Melan) writes:
> Dear Netlanders,
> 	We're currently having a problem with our protein gels.  Recently our
> gels have been showing beautiful resolution at the top of the gel but have
> been extremely fuzzy at the bottom.  We're using standard SDS-PAGE and have
> re-made all of our solutions but the problem persists.  We have reason however
> to suspect that our bis-acrylamide may be defective.
> 	Has anyone else had this problem???  Any suggestions? A month ago
> the gels were perfect and now all of a sudden they're not.  We're confused to
> say the least......so any and all suggestions are welcomed.  Thanks in advance.
> ===============================================================================
> Melissa Melan				Internet:(mmelan at lucy.wellesley.edu)
> Department of Biological Sciences
> Wellesley College
> Wellesley, MA  02181
> (617)283-3137
> ================================================================================

Two things that gave me similar problems were:

(1) The pH of the running buffer drifting too far. This can be caused by the
wrong pH to start with, or insufficient buffer capacity in the lower reservoir. 
Changing the buffer can help.

(2) Cruddy SDS. It may pay to check your source of SDS, put more in the gel
and/or put more in the running buffer. I would guess this is the more likely
cause given the sudden appearance of the problem.

Hope you find a fix.

Craig Marshall	Biochemistry Department	bioc07 at otago.ac.nz
		University of Otago	Phone 64 3 479 7871
		P.O. Box 56		Fax   64 3 479 7866
		Dunedin
		New Zealand