AMSBIO has announced two new histone deacetylase (HDAC)cell-based assay kits that provide a tool for studying the activity andinhibition of the full range of HDAC enzymes (1 to 11). The kits provide a fastand fluorescence-based method that eliminates radioactivity, extractions orchromatography, as are often used in traditional HDAC assays. By using acell-permeable HDAC substrate in the new assay kits, the activity of variousprotein lysine-specific deacetylases, including HDAC-containing complexes, canbe measured in intact cells in a simple and homogenous manner. The fluorescenceof the deacetylated reaction product can be analyzed using a plate reader or afluorometer. The new assay procedures require only two easy steps, eachperformed on a single microtitre plate. First, the HDAC substrate, whichcomprises an acetylated lysine side chain, is incubated with a samplecontaining HDAC activity. Second, deacetylation of the substrate sensitises thesubstrate, so that further treatment with the lysine developer produces afluorophore. Both the HDAC and HDAC class2a assay are well suited forhigh-throughput screening applications. HDAC inhibitors and antibodies,together with all 11 active HDAC enzymes, are available. Active Sirtuinproteins are also available separately.