Description_x000D_ General description_x000D_ Histone deacetylases (HDACs) are a large family of enzymes that remove acetyl groups from histone proteins. HDACs are localized in both the cytosol and nucleus and some shuttle between the two locations._x000D_ Sigma′s InSitu HDAC Activity Fluorometric Assay Kit provides a direct, fast, fluorescence-based method to measure HDAC activity in cultured cells. The procedure requires just two steps, both performed in the original 96-well cell culture plate. First, the cell culture medium is replaced with a cell permeable HDAC Substrate, containing an acetylated lysine side chain. During the subsequent incubation, HDAC Substrate enters the cells and is deacetylated by intracellular HDAC. In the second step, Developer is added to lyse the cells and cleave the deacetylated HDAC Substrate to release a fluorophore. The fluorescence generated can be quantified at Ex/Em = 368/442 nm. The assay is well suited for either individual or high throughput screening._x000D_ Application_x000D_ In Situ Histone Deacetylase (HDAC) Activity Fluorometric Assay Kit has been used to determine HDAC activity._x000D_ Biochem/physiol Actions_x000D_ Site specific histone acetylation and deacetylation have been shown to activate or repress eukaryotic gene transcription, respectively, and as a consequence, histone deacetylases (HDACs) play a crucial role in organism development and disease. Mutation or abnormal expression of HDAC is observed in cancer._x000D_ Features and Benefits_x000D_ • Simple two-step sensitive and reliable assay_x000D_ • All steps performed in the same cell culture plate_x000D_ • Utilizes fluorometric method_x000D_ • Sample type: cultured, adherent, and suspension cells_x000D_ • Suitable for individual tests or high throughput assays and kinetic studies_x000D_ • Convenient 96-well microplate format_x000D_ • Suitable for screening HDAC inhibitors or activators_x000D_ • Suitable for studying growth factors or other regulators that influence HDAC activity