Abstract
DNA of the transforming, nondefective Epstein-Barr virus (EBV) strain M-ABA, which is derived from nasopharyngeal carcinoma cells, was cloned as large overlapping pieces into the cosmid pHC79. The termini were cloned from closed circular virus DNA molecules out of M-ABA cell DNA in phage λL47. The large overlapping clones were used to prepare a library of subclones with inserts of 1–15 kb. A detailed restriction enzyme map of M-ABA virus DNA reveals the close similarity to isolates from other sources. The high number of tandem repeats in EBV DNA stresses the importance of using cloning vectors that can be propagated in
recA
−
Escherichia coli hosts.