Abstract
In this communication a report is made on hemagglutination by dengue virus (Hawaiian strain).
The results are summarized as follows.
The conditions of hemagglutination reaction:
1. A specific hemagglutinin was recovered from 2 to 4 day-old mouse brain infected with the virus of dengue.
2. The virus material was made into a 20% suspension with 5% glucose solution (pH 6.8), and further it was diluted two-fold in 1.5% calcium chloride solution (pH 6.8) to obtain a 10% suspension. The suspension was centrifuged at 9, 600 r. p. m. (8, 500 G) for 10 minutes.
The supernatant fluid was employed as the virus material.
3. 0.25% or 0.3% suspension of horse red cells and 1.5% calcium chloride solution (pH 6.8) were used respectively as blood cells and reaction medium.
4. Optimal temperature for the reaction was 4°C.
It was recognized that under those conditions dengue virus agglutinated horse red blood cells as high as 81, 920 to 163, 840.
Specific properties of hemagglutination reaction
Hemagglutination reaction by dengue virus was inhibited by dengue hyperimmune mouse and rabbit sera, but not inhibited by normal mouse, normal rabbit, mouse encephalomyelitis (GD VII) hyperimmune rabbit, influenza (PR 8) hyperimmune rabbit, polio. patient and normal human sera.
Accordingly the hemagglutination by dengue virus is considered as specific. In addition, mouse and rabbit sera contain a nonspecific inhibitor for the dengue hemagglutinins. However, it was confirmed that specific hemagglutination-inhibition antibody was readily separated from the normal inhibitor above mentioned by extration with chloroform.
