DNA transcription cannot take place unless DNA is unwound from the nucleosomes. The cell unwinds DNA by acetylation of lysine residues of histones. Research has shown that acetylation of non-histone proteins (e.g. transcription factors) and histones are involved in transcription. Histone acetyltransferases (HAT) acetylate the conserved amino-terminal domains of the four core histones (H2A, H2B, H3 and H4) on lysine residues, whereas histone deacetylases (HDAC) remove them. This pan-specific antibody recognizes proteins with acetyllysine residues. This antibody has been utilized for proteomic studies of protein acetylation, immunoaffinity chromatography separation and isolation of acetylated proteins and peptides from protease-digested whole cells.