Chromatrap, a business unit of Porvair Sciences, has published a new technical article that discusses and describes methodologies to increase Chromatin Immunoprecipitation (ChIP) efficiency by making sure chromatin in your samples is sheared to the correct size range.
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The authors describe how for every chromatin preparation it is essential to check the chromatin is sheared to fragments between 100-500 bp. They emphasise using a microfluidics platform is the most accurate measure of quantifying DNA.
Problems associated with over or under sheared Chromatin fragments are discussed and a protocol for optimised enzymatic shearing described. As some cells are resistant to lysis the authors also describe an optimised sonication methodology to ensure a successful ChIP result.