Use of the hemadsorption phenomenon for determining virus and neutralizing antibody titers of rabies

Abstract

Chicken embryo cells infected with the HEP Flury strain of rabies virus adapted to tissue culture produced a hemadsorption (HAD) phenomenon by using goose erythrocytes. The optimal conditions for HAD include the incubation of cell cultures at 37°C for 3 days after virus inoculated, the use of a 0.4% suspension of goose erythrocytes in phosphate buffer adjusted at pH 6.2, and adsorption of erythrocytes at 4°C. This phenomenon was inhibited with antirabies serum. Virus titer obtained with the HAD technique was almost the same as with the fluorescent antibody technique or the intracerebral inoculation of suckling mice. Results of the neutralization test by using the HAD technique could be easily determined 3 days after inoculation of chicken embryo cells with the mixture of 100 mean tissue culture infective doses of virus and diluted serum. The neutralizing antibody titers coincided with those obtained in mice.