[Superneutralization test--a new virus serology examination procedure]

The serum neutralisation test, based on the antigen-antibody reaction and cytopathic action of a given virus upon certain in-vitro cultured cell systems, was expanded to the dimensions of a super-neutralisation test by including specific control sera with known titre and applying then to all samples positive to serum neutralisation through repeated addition of virus to tubular cell cultures with no CPE in the serum neutralisation test. Another antigen-antibody reaction was introduced by repeated addition of virus. In samples with less antibody (lower titre) due to lacking or partial neutralisation of added virus such reaction gave a CPE of with the intensity was inversely proportional to the titre. The CPE (cytopathic effect) will disappear beyond a certain titre limit owing to complete neutralisation of added virus. The point of disappearance can be controlled to the purpose of the given test by appropriate choice of the virus dose. This approach will entail negligible extra expenses but enable, in addition to qualitative assessment of reagents, quantitative identification of their antibody titres, and this will, no doubt, add to the informative weight of the test result. The advent of the super-neutralisation test has added to laboratory diagnosis in the field of virus serology a conventiently applicable, uninvolved, and highly effective technique.