FIG. 2.

Chromatin assembly requires exogenous histones. (A) Outline of experiment. Plasmid DNA was incubated with only CD fraction or with CD fraction and yeast (y) or Drosophila (D) core histones. RT, room temperature; MNase, micrococcal nuclease. (B) Plasmid supercoiling. After assembly, plasmid DNA was reisolated, resolved by 1% agarose gel electrophoresis and stained with ethidium bromide. SC, supercoiled plasmid; R/OC, relaxed/open circular plasmid. (C) Micrococcal nuclease digestion assay. The product of the micrococcal nuclease digestions were resolved by agarose gel electrophoresis and visualized with ethidium bromide. M, 1 kbp plus DNA ladder.