A CONVENIENT AND EXPLICIT METHOD FOR HEMAGGLUTINATION AND HEMAGGLUTINATION-INHIBITION REACTION OF RUBELLA VIRUS

Abstract

The previous procedures of hemagglutination (HA) and hemagglutination inhibition (HAI) reactions with rubella virus was evaluated and an improved method giving more explicit results was established.
Baylor strain of rubella virus (MOI=about 1/2000) was inoculated in BHK-21 cell monolayer cultures with Eagle's minimum essential medium in Hanks' BSS without serum and incubated at 33°C using a roller drum.
High titer (32 to 128) of HA in the culture fluid was obtained continuously from 4 days after the infection for 6 days when the medium was exchanged every day. The harvested fluid was treated with Tween 80 and ethyl ether and resulted 2 to 8 folds increase of HA titer.
The improved procedures for HA test using Microtiter was as follows: The diluent for every factor was a phosphate buffered saline of pH 6.6 suplemented with 0.1% bovine plasma albumin and 0.2% goose erythrocyte suspension was used. Incubation was performed at 4°C for at least for 90 minutes. For HAI test, the sera to be examined were pretreated with 25% acid-washed kaolin and then absorbed with goose erythrocytes.
By the procedure, the convalescent sera from rubella patients usually showed the HAI antibody titer of 512 or more.