Chromatin plays important functions in regulating many biological processes, including DNA transcription, replication, and repair. The use of chromatin immunoprecipitation (ChIP) assays has contributed enor- mously to identify interactions between DNA and a wide range of nuclear proteins including histones and their different posttranslational modifi cations as well as a variety of transcription factors. ChIP assays have been successfully used to map histone modifi cations and histone variants, as well as binding of transcription factors and chromatin-modifying complexes in both, specifi c candidate loci and the entire genome. In this chapter, we provide a brief review of the variations in ChIP assays and a detailed explanation of the basic standard ChIP protocol