This protocol describes the chromatin preparation from fresh or frozen tissues. The isolated chromatin can be used for chromatin immunoprecipitation assays using Diagenode’s iDeal ChIP-seq kit (C01010051). The following protocol is optimized for 30-40 mg of tissue allowing up to 18 ChIP samples (1.5-2 mg of tissue per sample). However, the exact amount of tissue needed for ChIP may vary depending on protein abundance, antibody affinity etc. and should be determined for each tissue type.