Abstract
Histone deacetylases (HDACs) catalyze the deacetylation of lysine residues in their target proteins. This biochemical modification can have profound effects on the functions of these proteins and a dysregulation of HDAC activity contributes to severe diseases, including neoplastic transformation. In the following chapter, we present a strategy that allows to distinguish between the inhibition of the class I HDACs HDAC1, 2, and 3 and of the class IIb HDAC HDAC6. This method is based on Western blot and relies on the detection of hyperacetylated substrates of class I or class IIb HDACs in lysates from cells that were treated with histone deacetylase inhibitors (HDACi).