Autoradiography of chromosomal DNA fibers from Chinese hamster cells.

Abstract

Linear DNA autoradiograms are found when the Cairns technique is applied to Chinese hamster cells. At least 6% of these autoradiograms are more than 0.8 mm long-roughly the size of the Escherichia coli chromosome and considerably longer than previously reported DNA fibers from higher organisms. Some rare autoradiograms are as long as 1.6-1.8 mm. The implications of these results in terms of models of chromosome structure are disc ussed.