Observations on a Cell Line Producing Mammary Tumor Virus23

Abstract
Preliminary tissue culture and electron microscope studies of the cells of ATCC #CCL-51 were undertaken to characterize this cell line. Cells of CCL-51 have been actively producing tumor-inducing mammary tumor virus since the line was initiated in 1962. No specific changes in cellular morphology could be related to the production of mammary tumor virus. An unexpected finding was the relatively few type A particles seen in the cells of CCL-51.