The acetylation of histone lysine residues plays a crucial role in the epigenetic regulation of gene transcription. The isolated individual or tandem bromodomains of BRD2 and BRD4 have been shown to bind acetylated histone tails, serving to couple histone acetylation marks to the transcriptional regulation of target promoters. Small molecule inhibitors of bromodomain/histone interactions hold promise as useful therapeutics for human disease. Cayman's BRD4 bromodomains 1 and 2 TR-FRET Assay Kit is a homogeneous, TR-FRET assay method amenable to rapid characterization of inhibitors of bromodomain/acetylated peptide interaction in a high throughput format. This screening assay is robust, displaying a Z' >0.6.