New SimpleChIP® Enzymatic Chromatin IP Kits from Cell Signaling Technology (CST) are co-developed by CST and NEB scientists and therefore contain the highest quality research reagents. These kits are available with either Protein G agarose or Protein G magnetic beads and contain all buffers and reagents needed to perform up to 30 ChIP assays. Reagents supplied in the kits are the product of in-house ChIP validation at CST, simplifying your optimization. The kits can be utilized with any ChIP-validated antibody to detect endogenous levels of protein-DNA interactions and histone modifications in mammalian cells. Protein G agarose and Protein G magnetic beads are also available as separate products.
Enzyme-based and sonication-based ChIP kits produce chromatin fragments of a similar size. Chromatin was prepared from 4 x 107 HCT116 human colorectal carcinoma cells according to the protocols included with the SimpleChIP® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003 or a competitor’s sonication-based ChIP kit. DNA was purified from each chromatin sample and DNA fragment size was determined by electrophoresis on a 1% agarose gel. Both enzymatic digestion with the SimpleChIP® Kit (lane 1) and sonication with the competitor’s kit (lane 2) produced chromatin fragments ranging from 150 to 700 bp, corresponding to one to five nucleosomes in length.
SimpleChIP® digested chromatin is more conducive to immunoprecipitation than sonicated chromatin. Chromatin immunoprecipitations were performed with 10 μg of cross-linked HCT116 chromatin and the indicated antibodies, using SimpleChIP® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003 or a competitor’s sonication-based ChIP Kit. The enriched DNA was quantified by qPCR. The amount of immunoprecipitated DNA in each sample is presented as a percent of the total input chromatin. For every target tested, enzyme-digested chromatin showed better enrichment of target DNA loci than did sonicated chromatin.