Tue Dec 8 11:58:00 EST 1992

There are many factors that will affect immunoprecipitation, e.g. salt
concentration, Triton concentration and other components in the
mixture. (I do not think that "the extract is too crude" is a factor
here.) Since you did not provide enough information and I do not know
how to answer your question. One point I want to make is that do you 
know your antibody recognize both nature and denatured forms of your
protein. Nowdays people like to use protein from SDS gel as antigen
and the produced polyclonoal antibodies do not necessarally recognize
nature form of the protein. If you are not sure, do a Western on a
non-denaturing gel e.g. regular gel (without SDS) or IEF gel. 

More information about the Methods mailing list