PurifiedPurified (>90% pure). Crude blend of extracted histones that are unfractionated and unpurified. May contain numerous subfractions due to acetylation, methylation and phosphorylation of various amino acid residues. Autoantibodies to histone antigens have been described in patients with idiopathic and drug-induced SLE, rheumatoid arthritis, and other conditions. Histones are a group of similar, small, highly conserved nuclear proteins that bind to DNA by their many basic residues. The