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：1981
卷号：78
期号：12
页码：7575-7578
DOI：10.1073/pnas.78.12.7575
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：With standard protocols for DNA infection, only a small fraction (about 4%) of monkey cells exposed to purified DNA of simian virus 40 (SV40) exhibits signs of infection. We have devised a protocol by which we can extend the time of exposure of BSC-1 cells to DNA in the presence of low concentrations of DEAE-dextran. The efficiency of infection is proportional to the time of exposure. With an 8-hr exposure, we are reproducibly able to infect 25% of the cells, and we have been able to achieve levels of infection as high as 50% with a 16-hr exposure. The percentage of cells infected was measured either by scoring for nuclei positive for SV40 tumor antigen or by an infectious centers assay. We also report the use of ethidium bromide as a nonspecific nuclear counterstain in the immunofluorescence assay for SV40 tumor antigen.
