An improved version of the early histone HCl extraction protocol

Acid extraction has been and remains one of the most widely used methods for preparing histones. Over the years, dilute hydrochloric or sulphuric acid solutions have been used alternately for histone extraction, followed by acetone or trichloroacetic acid precipitation, respectively. Although a sulphuric acid method has become commonplace in recent years, the protocol is quite involved and can pose problems when trying to solubilize the histones obtained this way. In this paper, we describe an alternative approach based on an early protocol using hydrochloric acid. The new method is technically straightforward and produces histones that are readily amenable to downstream uses, including sodium dodecyl sulfate, acetic acid-urea-Triton X-100, two-dimensional polyacrylamide gel electrophoresis, and mass spectrometry.