Purification and properties of Herpesvirus saimiri DNA

³H-Thymidine-labeled Herpesvirus saimiri (HVS) was purified from supernatant and cells of infected owl monkey kidney monolayer cultures. Pronase/SDS-extracted HVS DNA was characterized in neutral sucrose gradients. Cocentrifugation of this DNA with ¹⁴C-labeled T4-phage DNA resulted in s⁰₂₀, w = 58 ± 1.5 S as the sedimentation constant, corresponding to a molecular weight of 91 ± 5 × 10⁶ daltons. Unsheared HVS DNA banded in cesium chloride at 1.709 g/ml, but it broke down during the different manipulations to at least two double-stranded DNA molecules of largely different base composition which shared no sequence homologies. One part (42% of the total viral genome) had a density of 1.729 g/ml, corresponding to 70% cytosine plus guanine content, the other one (representing 58% of the intact molecule) banded at 1.694 g/ml, corresponding to 35% cytosine plus guanine.