Immunoprepitation Kit: Immunoprecipitation (IP) allows purification of a protein from a complex mixture of proteinsusing a specific antibody and a matrix that binds to the antibody. The matrices commonly used are agarose or sepharose bound Protein A or protein A/G PLUS. IP followed by SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and immunoblotting are routinely used in a variety of applications: to measure the molecular weights of protein antigens, to study protein/protein interactions, to determine specific enzymatic activity, and to monitor protein post-translational modifications. The IP technique also enables the detection of rare proteins, which may otherwise be difficult to detect, since immunoprecipitation can concentrate these proteins as much as 10,000-fold.