Figure 2.

Photograph of an agarose gel containing electrophoretically separated DNA fragments and stained with ethidium bromide. Vero cells were mock-infected (lane 1) or infected with HSV-1(F) (lane 2), HSV-1 d120 mutant (lane 3), HSV-1 120FR mutant (lane 4), or HSV-1 120KR mutant (lane 5). At 30 hr after infection, 2 × 10⁶ cells per sample were collected, rinsed with PBS, lysed in a solution containing 10 mM Tris⋅HCl at pH 8.0, 10 mM EDTA, and 0.5% Triton X-100, and centrifuged at 12,000 rpm for 25 min in an Eppendorf microcentrifuge to pellet chromosomal DNA. Supernatant fluids were digested with 0.1 mg of RNase A per ml at 37°C for 1 hr and then for 2 hr with 1 mg of proteinase K per ml at 50°C in the presence of 1% sodium dodecyl sulfate (SDS), extracted with phenol and chloroform, and precipitated in cold ethanol and subjected to electrophoresis on horizontal 1.5% agarose gels containing 5 μg of ethidium bromide per ml. DNA was visualized by UV light transillumination. Photographs were taken with the aid of a computer-assisted image processor (Eagle Eye II; Stratagene).