Use of polyethylene glycol-treated calf serum for cell cultures in virus and interferon studies.

Immunoglobulins and lipoproteins can be efficiently removed from calf serum by precipitation with polyethylene glycol (PEG) 6000 under sterile conditions. The PEG-treated serum is suitable for cell cultures used for virus growth and assays. Moreover, PEG was found to slow down the growth of L cells and to enhance the production and activity of mouse interferon.