Restriction enzyme analysis of human cytomegalovirus using DNA extracted from infected cells

Cytomegalovirus (CMV) isolates were investigated by restriction enzyme analysis. A method for extraction of cellular CMV DNA is described which uses CMV DNA released into the Hirt supernatant after precipitation of cellular DNA. CMV DNA is further purified by ultracentrifugation in neutral sucrose gradient. Fifteen strains from unrelated patients all had unique cleavage patterns with three restriction enzymes, although many of the fragments comigrated. Strains from related patients mostly showed identical patterns. The CMV genome seems to be stable since the pattern did not change in five isolates obtained from the same patient during a 5-year period.