ABSTRACT
The possibility for viral contamination exists in established cultures as well as in primary cultures. The use of established genetically engineered cultures in the production of biologicals for human use requires that these cultures be monitored for adventitious viral agents. Among the methods used for this purpose are animal inoculation and in vitro assays which provide a broad-spectrum screen for viral agents. Many of the cell cultures which were earlier established for vaccine production can be used as sensitive detector cell lines in screening for viruses which might be present in other cell cultures. Because of the possible contamination of cell cultures by bovine viruses present in serum, cells which have been in culture for long periods of time should be screened for the possible presence of contaminating bovine viruses. After hybridization testing and antibody testing, the virus was determined to be of bovine origin, probably introduced into the culture from calf serum used to supplement the culture medium.
