ChIP assays were performed using HeLa cells, the Bioss antibody against H3K9me2 (bs-53118R) and optimized PCR primer sets for qPCR. ChIP was performed with an Auto Histone ChIP-seq kit, using sheared chromatin from 1 million cells. A titration of the antibody consisting of 1, 2, 5, and 10 \u03bcg per ChIP experiment was analyzed. IgG (2 \u03bcg\/IP) was used as negative IP control. QPCR was performed with primers specific for the promoter of the inactive HBB gene and the coding region of the inactive MYOD gene, used as positive controls, and for the promoters of the active genes c-fos and GAPDH, used as negative controls. The figure shows the recovery expressed as a % of input (the relative amount of immunoprecipitated DNA compared to input DNA after qPCR analysis).