The Ultrastructure of the Nuclear Envelope as Seen in Replicas from Normal and Neoplastic Nuclei

Summary A method of preparing carbon replicas of isolated liver and tumor nuclei is described which enables large areas of the nuclear surface to be examined. Two types of structure may be recognized: the first, large and irregular elevations thought to be due to nucleoli within the nucleus and, second, large numbers of small circular elevations 0.25 µ in diameter covering the whole surface. The appearance is compared with the results obtained by sectioning isolated nuclei and the tissues from which they were derived.