特定长度染色质的电子显微镜观察。

Finch J T, Noll M, Kornberg R D

Proc Natl Acad Sci U S A. 1975 Sep;72(9):3320-2. doi: 10.1073/pnas.72.9.3320.

Defined lengths of chromatin were prepared by brief digestion with micrococcal nuclease and fractionation in a sucrose gradient. A length containing a given number of 200 base pair repeating units appeared as the same number of 100 A beads in the electron microscope. The distance between beads within a length was small, usually less than about 20 A.

通过用微球菌核酸酶短暂消化并在蔗糖梯度中分级分离来制备特定长度的染色质。在电子显微镜下，含有给定数量200个碱基对重复单元的一段长度表现为相同数量的100埃珠。一段长度内珠子之间的距离很小，通常小于约20埃。