Individual human histones H3 and H4, but not octameric core histones, trigger TG in PRP. TG performed in recalcified PRP containing individual human histone proteins was compared with that of recombinant core histone octamers (A) or purified calf thymus histones (B). CThist, mixture of purified calf thymus histones; rOctamer, octameric core histone reconstituted with recombinant human histone proteins. Panels A and B are representative of 3 independent experiments.