help needed on gel retardation assay

[Tao Wei]

Dear netters:

I am a graduate student and working with tomato plant.  I am running into  
a problem in gel retardation experiments.  The DNA probe (200 bp prepared  
by PCR) and crude nuclear proteins seemed to form very large complexes  
(because of non-specific interaction?), stuck on the bottom of wells and  
could not get into the gel.  The condition of binding reaction was pH 7.5,  
50 mM NaCl, 9-11% glycerol and some competitor DNA.  Does anybody have any  
suggestions to help me out? Thank in advance.

Tao Wei
The Graduate Program in Molecular Biology
New Mexico State University
twei at dante.nmsu.edu