Effect of diethylaminoethyl-dextran on the replication of a murine sarcoma (Moloney)-leukemia virus complex in mouse embryo cultures (38577).

Isolates of a sarcoma (Moloney)-leukemia virus complex prepared as cell-free extracts from mouse tumors showed no enhancement in infectivity by DEAE-D either in the sarcoma moiety measured by focus formation or in the leukemia moiety measured by XC cell assay. The sarcoma moiety was not enhanced by DEAE-D in MEM and modified McCoy's 5a media or when varying amounts of FCS and glutamine were included in the media. Progressive enhancement of viral infectivity by DEAE-D was found when the viral preparations were passaged serially in MEF cells. DEAE-D ALSO ENHANCED TUMOR FORMATION IN VIVO BY TISSUE CULTURE PASSAGED VIRUS.