Detection of viruses by chemical and biological means.

The discovery of the polyoma virus ( 80 ) pro vides the strongest incentive yet for continued serious efforts to find a human cancer virus. Ac cording to previous experience in the field of ani mal viruses, the polyoma virus should prove to be one member of a group of related viruses with different species specificities, causing similar dis eases. When attempts to isolate human viruses have failed, we have reason to question the suit ability of the materials and methods used. This attitude served as a basis for the present discus sion of virus detection by biochemical and bio logical means. An attempt was made to envisage situations in which a virus would not be readily detected and to analyze the reasons for this, rather than summing up the various current tech nics for virus detection and their limitations. For this purpose the discussion was grouped under three headings, corresponding to the known stages in the developmental cycle of viruses: provirus, vegetative virus, and mature virus.1