Fig. 4. ChIP analysis of CENP-A and CENP-B on introduced alphoid YAC DNA. (A) Positions of PCR primer pairs on alphoid YAC DNA are indicated. (B) Standard curves of real-time PCR using the primer pairs indicated in A and sequentially diluted input DNAs. All the primer pairs showed a concentration-dependent amplification of the target sequences. (C-F) Fixed and sonicated chromatin from the cell lines indicated was immunoprecipitated with mouse normal IgG, anti-CENP-A antibody, and anti-CENP-B antibody. The immunoprecipitated DNA was quantitated by real-time PCR using the primers indicated in A. (C) The bar charts show the percentage recovery (% IP) of 5S ribosomal DNA fragment by immunoprecipitation using the indicated antibodies. (D-F) The bar charts show the relative enrichment, calculated by dividing the % IP of each DNA region by that of the 5S ribosomal DNA fragment immunoprecipitated by normal mouse IgG (D), anti-CENP-A antibody (E) and anti-CENP-B antibody (F). ChIP analysis was performed four times and the average of the results is presented. The colors of the columns denote the different DNA sequences as shown in A. Bars indicate s.e.m.