Abstract
Herpes simplex virus was highly purified from host cell material with little loss of infectivity by the combination of isopycnic centrifuging in a three layered silica gradient and rate zonal centrifuging in dextran T 70 gradient. By layering three solutions of colloidal silica (24, 18 and 12%, w/v) on top of each other in the centrifuge tube prior to ultracentrifuging, a linear type of gradient was obtained. Virus particles and nucleocapsids seemed to be distinctly separated in this three-layered silica gradient. The overall reduction of host proteins and sphingolipids was 1250 to 2000 times and 350 to 600 times, respectively. The reduction of virus specified non-particulate proteins was approx. 500 times. The recovery of infectivity was 55 to 70%.