Protocol for chromatin immunoprecipitation of histone modifications in frozen adipose tissue

Chromatin immunoprecipitation (ChIP) combined with sequencing has revolutionized our understanding of gene regulation; however, its application to frozen adipose tissue presents unique challenges due to the high levels of lipid content. Here, we present a protocol for ChIP of histone modifications in human frozen adipose tissue. We describe steps for tissue preparation, chromatin isolation, sonication, pre-clearing of chromatin, and immunoprecipitation. We then detail procedures for elution, crosslink reversal, chromatin purification, quality control, and library synthesis.