Patent ID: 8163481

Claim:
A method of isolating a chromatin fraction containing histone H1, H3 and H4 proteins from an intact cell comprising: a. lysing cells in a first solution comprising an enzyme-inhibitory concentration of a chaotropic reagent to produce a lysate comprising released chromatin, wherein either: i. the first solution comprises an ionic salt; or ii. an ionic salt is added to the lysate, wherein the ionic salt is included in the first solution or is added to the lysate in an amount effective, in the lysate, to prevent chromatin expansion and to facilitate dissociation, inactivation and extraction of cellular components other than H3, H4 and H1 from the chromatin; b. separating the released chromatin from cellular components other than H3, H4 and H1 histone proteins; and c. collecting the released chromatin.