Chromatin Immunoprecipitation Assay (ChIP)

Chromatin Immunoprecipitation Assay, also known as the ChIP assay allows one to determine the mechanism of trascriptional repression, by immunoprecipitating chromatin with antibodies. ChIP involves formaldehyde treatment of a cell population to cross-link proteins to their target DNA in vivo, cell lysis, sonication to fragment chromatin, and then immunoprecipitation of specific chromatin complexes using an antibody against the protein of interest. After removal of the cross-links, PCR amplification at a selected locus, or slot blot hybridization using a specific probe is performed.