Immunoprecipitation protocol

[Guilfoyle Lab]

Hi, 
I'm trying to study some protein-protein interactions using in vitro
translated HA-epitope-tagged proteins. I need a reliable protocol for 
doing immunoprecipitations from these in vitro translation reactions
using monoclonal 12CA5 which recognizes HA epitope. So far it looks like
I'm having high background problem coming from non-specific binding to
Protein A-Sepharose beads.
Any suggestions, references or hints would be greatly appreciated.

Thanx,

Tim Ulmasov
Biochemistry,
University of Missouri-Columbia
bichguil at mizzou1.missouri.edu