Inhibition of histone deacetylase (HDAC) has been implicated to modulate transcription and to induce apoptosis or differentiation in cancer cells. However, screening of compounds for HDAC inhibition has been difficult due to the lack of convenient tools for analyzing HDAC activity. The new HDAC Inhibitor Drug Screening Kit provides a fast, fluorescence-based method that eliminates radioactivity, extractions, or chromatography, as used in traditional assays. The new procedure requires only two easy steps, both performed on the same microtiter plate. First, your inhibitor candidates are mixed with HeLa Nuclear Extract and HDAC fluorometric substrate, which comprises an acetylated lysine side chain. Deacetylation of the substrate sensitizes th