Abstract
Epstein-Barr virus (EBV) is usually obtained from supernatant fluids of cultures of primate lymphoblastoid cells. The isolation of small amounts of virus particles from large vol. of culture fluid offers particular problems because of the osmotic fragility of herpes viruses, and attempts to concentrate biologically active EBV by zonal centrifuging in solutions containing sucrose have been unsuccessful. It is shown here that EBV particles can be conveniently concentrated from culture fluids with polyethylene glycol. The biological activity of the concentrated particles is retained, as measured by a superinfection assay, and good yields are obtained from supernatant fluids containing as little as 2 x 102 EBV particles/ml.