I'm trying to digest bovine sperm DNA with MNase for ChIP-Seq but I can't get the nucleosome band (around 150 bp) in the agarose gel. I followed the Hisano et al. protocol (Genome-wide chromatin analysis in mature mouse and human spermatozoa) with different MNase concentrations (10, 15, 20, 30, 40 U/2 millions) and DTT pre-treatment (50 mM/2 hours) but in all cases the DNA looks overdigested.
Does anyone have an idea of what I could try different?
Thank you!