期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：10
页码：4873-4876
DOI：10.1073/pnas.75.10.4873
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A purified system is described for the introduction of negative supercoils into simian virus 40 DNA. The system consists of histones H2A, H2B, H3, and H4, DNA-relaxing enzyme, and a purified factor from Xenopus laevis stage 6 oocyte nuclei. The nuclei are prepared en masse by the technique of F. Scalenghe, M. Buscaglia, C. Steinheil, and M. Crippa [(1978) Chromosoma 60, 299-308]. The supercoiled simian virus 40 DNA prepared by this method is indistinguishable from simian virus 40 supercoiled DNA prepared from infected monkey cells.
