ChIP analysis of sheared chromatin from 10? HeLa cells using GTX60351 Histone H3K27me2 (Di-methyl Lys27) antibody - ChIP grade. A titration of the antibody consisting of 1, 2, 5, and 10 microg per ChIP experiment was analysed. IgG (2 microg/IP) was used as negative IP control. QPCR was performed with primers for the promoter of the active GAPDH and EIF4A2 genes, used as negative controls, and for the promoter of the inactive HBB and the coding region of the inactive MYOD1 genes, used as positive controls. This figure shows the recovery, expressed as a % of input (the relative amount of immunoprecipitated DNA compared to input DNA after qPCR analysis). These results are in accordance with the observation that H3K27me2 is preferably present at silent genes.