Isopycnic centrifugation of sheared L-cell chromatin in metrizamide gradients.

Isopycnic gradient centrifugation of L-929 cell chromatin in a 38% (W/V) metrizamide solution yields two distinct fractions. The fraction banding at a density of 1.24 gm/cm(2) (H chromatin) contains about 10% of the DNA present in the fraction banding at a density of 1.18 gm/cm(2) (L chromatin). Both fractions contain the same proportions of satellite to main band DNA's. Some differences can be seen in the DNA: protein ratios and types of proteins present in the H and L chromatin fractions.