Developmental analysis of AcH3 and AcH4 association at the 3′ RR. ChIP assays were performed on chromatin from the MEL cell line (A), 18-81 pre-B cell line (B), A20 mature cell line (C), and MPC11 plasma cell line (D). No antibody and IgG serve as experimental controls. While β-globin and CAD (the gene encoding carbamoyl-phosphate synthetase II [EC 6.3.5.5], aspartate transcarbamylase [EC 2.1.3.2], and dihydroorotase [EC 3.5.2.3]) serve as positive controls, Eμ is used as a negative control in the MEL cell line. CAD and the β-globin gene are used as a positive and a negative control for histone acetylation, respectively, in B cells. The primers used are indicated next to relevant gels. Shown are serial (1:3) dilutions of input and IP samples for the semiquantitative PCR analysis. The signal for hs1,2 in the input of MPC11 is absent due to a technical error.