SDS-PAGE gel resolution

[A. F. Simpson]

Martin Thompson wrote:
> 
> I was wondering if anyone knows what kind of factors influence how
> 'fuzzy' bands are on a SDS-PAGE gel.  Currently I am having problems
> with this and would like to know how to increase the sharpness or
> resolution of these bands.

Running the gel itself too fast (and too hot) can cause fuzzy bands. 
Try reducing the current and seeing if things improve.  Do you use a
prestained marker?  That's the best way to keep an eye on the run.

Are the bands fuzzy on the gel or only after blotting?  A friend had
trouble with fuzzy bands which was eventually traced to trying to run
the semi-dry blotter at too high a power.  I don't know if the same
effect would occur on wet blotting.  I have always taken a 'tortoise'
approach to blotting, so I've never encountered such a problem
personally.

Can you give a few more details?  (E.g. type of sample, MW of the
protein you're looking for, size/type/percentage of gel, what staining
you used to visualise the 'fuzziness'.)  The more detail you give the
more chance there is someone can give a helpful response.

> Thanks in advance,
> Marty.

love
Anna