Chromatrap has published a technical article that discusses and describes methodologies to increase Chromatin Immunoprecipitation (ChIP) efficiency by making sure chromatin in samples is sheared to the correct size range.
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 provide an optimised sonication methodology to ensure a successful ChIP result.
For a copy of the article, click here.
