Chromatin is the complex of genomic DNA and associated proteins in the nucleus. This higher ordered structure of DNA allows cells to package their DNA, provides a scaffold for cell division, and enables control of gene expression. Chromatin structure, bound by a dynamic repertoire of proteins, alternates between condensed heterochromatin and extended euchromatin.
Chromatin Immunoprecipitation
Chromatin Immunoprecipitation (ChIP) is a powerful technique for studying protein-DNA complexes. Specific antibodies enrich for regions of chromatin that contain the protein of interest, and various detection methods are employed to detect specific DNA sequences within the enriched chromatin.
Chromatin is the natural state of DNA in the nucleus, and all DNA-related processes function in chromatin rather than on naked DNA. Because transcriptional or post-transcriptional regulation on naked DNA can differ from that on assembled chromatin, it is crucial to have a reliable method for assembling and analyzing chromatin in vitro.
EMD Millipore’s proteins for in vitro chromatin assembly include histone chaperone NAP-1, which regulates chromatin fluidity, and Acf1/ISWI, a chromatin remodeling complex required for replication through heterochromatin. EMD Millipore’s purified histones complete the assembly reaction. After combining NAP-1 with histones, followed by Acf1/ISWI, histones are deposited into nucleosome arrays in an ATPdependent manner. The resulting DNA is perfect for in vitro transcription, chromatin immunoprecipitation, or analysis of chromatin assembly process.
