Chromatin immunoprecipitations were performed with cross-linked chromatin from 4 x 10 6 HeLa cells and either 10 μl of Rpb1 CTD (4H8) Mouse mAb or 2 μl of Normal Rabbit IgG #2729 using SimpleChIP ® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003. The enriched DNA was quantified by real-time PCR using SimpleChIP ® Human RPL30 Exon 3 Primers #7014, SimpleChIP ® Human GAPDH Exon 1 Primers #5516, SimpleChIP ® Human MyoD1 Exon 1 Primers #4490, and SimpleChIP ® Human MYT-1 Exon 1 Primers #4493. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin, which is equivalent to one.