Very high background!!! Help!

[Dr. L. Darjania]

Dear Netters

Currently I am working  on  cAMP mediated external signal transduction in 
guard cell protoplasts of Vicia faba.  Particularly I study the role of 
cAMP-dependent protein kinases in that process, using intact protoplasts 
radiolabelling with  32Pi  and following separation of phosphoproteins by 
SDS-PAGE.

Unfortunately,  numerous experiments showed a very high background in the 
gel making problems in autoradiography. 

Can anybody gave me some protocol allowing an efficient elimination of 
such high background?

Thank you very much for your information.

Dr. L. Darjania

e-mail: darjania at criba.edu.ar