Silver staining of histones in Triton-acid-urea gels

A reliable method for silver staining histones in Triton-acid-urea gels was developed. Optimum staining is achieved by treating the gels either with amido black or a colorless, water-soluble analog of amido black, 2,7-naphthalenedisulfonic acid, prior to staining with ammoniacal silver. Staining of purified calf thymus histones H2A, H2B, H3, and H4 by this method is 30 times more sensitive than staining with amido black alone, allowing the detection of each histone and its modified forms down to the nanogram level. The use of 2,7-naphthalenedisulfonic acid dramatically shortens the procedure permitting histone patterns to be visualized within 5 h.