62 Analysis of reverse transcriptase (RT) nucleotide sequences from AZT resistant strains of HIV-1 suggest further possible sites of mutation may be involved in the development of drug resistance: Levantis, P., Stein, C. A., ∗Ekstrand, H., ∗Gronowitz, S. and Oxford, J. S.; London Hospital Medical College, Academic Virology, Turner Street, London E1 2AD, UK; ∗Unit of Replication Enzymology, University of Uppsala, Uppsala, Sweden