The 895-8 isolate of the Epstein-Barr virus (EBV) has been described as a non-lytic transforming virus. We have performed experiments in order to determine if the B95-8 EBV is capable of super-infecting and replicating in EBV-genomepositive non-producer lymphoblastoid cells. Using concentrates of 895-8 EBV, prepared from 6 different 895-8 cell lines treated with 12-0-tetradecanoylphorbol-13-acetate (TPA), we demonstrated that virus concentrates could transform human or cotton-top tamarin B-lymphocytes and also lytically replicate in Raji cells, inducing EBV antigens and infectious virus. While the virus obtained from B95-8 super-infected Raji cells was able to transform cord-blood lymphocytes (CBLr) and super-infect Raji cells, transformation was abortive, with cell cultures only growing for up to 6 weeks. Transformation titers of the 895-8 virus concentrates ranged from I O5 to > lo8 transforming unitdml; early antigen (EA) induction ranged from I% to 50% after superinfection of Raji cells, depending on the virus stock used, as determined by immunofluorescence. Southern blot analysis was carried out on the DNA prepared from B95-8 cells and virion DNA. The results were consistent with the published EcoRl restriction pattern for 895-8 EBV. The issue of whether the 895-8 cells produce virions with a dual biological phenotype or, rather, 2 biologically distinct viruses, is addressed.