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：1979
卷号：76
期号：8
页码：4117-4121
DOI：10.1073/pnas.76.8.4117
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Studies of mouse mammary tumor virus (MMTV) have been impeded by the lack of an in vitro infectivity assay. We have developed a rapid, quantitative in vitro assay for MMTV infectivity based on the detection of positively staining foci by immunoperoxidase. This assay and a 50% end-point titration of MMTV infectivity gave identical virus titers. Infection of a rat hepatoma cell line, a feline kidney cell line, and a normal murine mammary gland cell line by virus from the mouse mammary tumor GR3A cell line was linear with respect to virus concentration. The infectious titers obtained in both homologous and heterologous cell lines were not significantly different, demonstrating a lack of host range specificity. Virus infectivity was inactivated by heating at 55 degrees C and by ultraviolet irradiation. Rabbit anti-MMTV serum neutralized the infectivity with a 50% neutralization end point of 1:5000. Applications of this assay to the study of the immunological, biological, and biochemical characteristics of MMTV are discussed.
