The difference between IP and coIP
Co-immunoprecipitation (coIP) is a protein extraction technique that specifically targets protein-protein interactions. It is slightly different from immunoprecipitation. Immunoprecipitation utilizes antibodies immobilized on a mobile support to capture target proteins. Co IP protocol takes this concept one step further by using antibodies to target not only the direct antigen that binds to the antibody, but also any protein that binds to the antigen and is pulled out with it. This makes co-ip protocol an ideal technique for studying protein complexes. The main concern when developing a co-ip protocol is to ensure that the lysis, wash, and elution buffers do not denature the proteins. Otherwise the tertiary structure of the proteins will deteriorate and the protein-protein interaction may be altered or completely lost.