Fig. 27.3.

PCR validation of a ChIP experiment. An antibody to RNA polymerase II (Pol) is used as a positive control and normal rabbit IgG serves as a negative control. Success of the ChIP experiment is evaluated by comparing the amplified PCR fragments to dilutions of the 10% input sample. Enrichment of Pol at the active GAPDH promoter is equivalent to 0.2% of input (1:50 dilution of 10% input), while IgG shows no significant enrichment. Neither Pol nor IgG is enriched at the negative control region (3′-end of ZNF333). These results are typical for a successful RNA polymerase II ChIP experiment.