RESUMEN
The results of comparative studies on concentration and purification of herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) by ficol density gradient centrifugation are presented. A two-phase distribution of extracellular HSV was established in phycol density gradient centrifugation: in zones with density of 1.110-1.114 and 1.088-1.085 g/ml. The effectiveness of purification of HSV preparations recovered from the corresponding gradient zones was determined by electron microscopy and quantitation of the contaminating cellular (radioactive) proteins in virus purification from a mixture of the culture fluid from infected cultures and the culture fluid from uninfected labeled human embryo skin-muscle tissue cultures (HESM) and a mixture of unlabeled extracellular HSV and a homogenate of labeled uninfected HESM cultures. In HSV purification from the virus-containing culture fluid the amount of cellular proteins was shown to decrease 500-fold in 150-fold virus concentration. In purification of extracellular HSV from the mixture with cell homogenate the amount of cellular proteins decreased 70- and 100-fold for HSV-2 and HSV-1, respectively. The infectious virus yield in phycol gradient centrifugation of a precipitate obtained by the addition of polyethylene glycol-6000 to the culture fluid for HSV-1 was 34.7% (in titrations in HESM cultures) and 38.4% (by intracerebral inoculation of mice weighing 5-6 g), and for HSV-2 20.2% and 26.3%, respectively.