Enrichment profiles for H3K9ac and H3K9m3 expressed as log2 ChIP/input ratios in Q2ChIP-chip and μChIP-chip assays. (a) Comparison of enrichment profiles over a 360-kb region (H3K9ac) and a 300-kb region (H3K9m3) of chromosome 12 obtained by Q2ChIP-chip and in two μChIP-chip replicates. (b) Detailed profiles of H3K9ac and H3K9m3 enrichment on the 3-kb tiled regions (shown in bottom panels) of the POU5F1, NANOG, SOX2, TRIM40 and ESR1 promoters. Log2 ChIP/input ratios are shown in black and H3K9ac or H3K9m3 peaks (FDR ≤ 0.05) are superimposed (shaded in red). Tiled regions (bottom panel) also show the region examined by ChIP-qPCR (blue bars) in Figure 4.