To determine whether MeCP2 was associated with ERα promoters, we conducted a ChIP assay. Cortical tissue was taken from female mouse pups at PND 4, 10, and 18. Nuclear proteins were then cross-linked, and sheared chromatin was immunoprecipitated with MeCP2 antibody (Ip). Recovered chromatin was amplified by standard PCR using primers spanning regions of exon A or exon C. Nonimmune IgG was used in all ChIP reactions as a control. An ethidium bromide-stained gel of PCR products showed a representative of ChIP analysis. In, Input; NI, nonimmune IgG antibody.