ChIP assay was performed using human U2OS cells, the antibody against H3K4me3 (bs-53028R) and optimized PCR primer pairs for qPCR. ChIP was performed using sheared chromatin from 2 million cells and stringent washing conditions. A titration consisting of 1, 5 and 10 μl of antibody per ChIP experiment was analyzed. IgG (1 μg/ IP) was used as a negative IP control. Quantitative PCR was performed with primers for the promoter of the constitutively expressed GAPDH gene and for myoglobin exon 2. 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 trimethylation of K4 at histone H3 is associated with the promoters of active genes.