FIG. 1.

Identification of site-specific alkali-sensitive regions within HCMV oriLyt. Viral DNA isolated from sucrose gradient centrifugation was cleaved with NheI and incubated at 70°C in 50 mM NaOH or 50 mM NaCl. Samples were neutralized with Tris-HCl (pH 7.0), separated on a 5% denaturing polyacrylamide gel, transferred to a nylon membrane, and hybridized with pOri. Lanes: 1, AD169 DNA treated with NaCl; 2, AD169 DNA treated with NaOH. The arrow indicates the presence of a 550-base band on NaOH-resistant DNA.