Hemagglutination with avian infectious laryngotracheitis virus

Avian infectious laryngotracheitis virus grown in primary chicken kidney cell cultures was tested for hemagglutination (HA) with erythrocytes of a variety of species at 4 degrees C, 22 degrees C, and 37 degrees C. HA was observed at all temperatures with mouse erythrocytes but not with cattle, sheep, goat, swine, rabbit, guinea pig, chicken, and goose erythrocytes. A strain variation between mice in the agglutinability of their erythrocytes necessitated selection of mice to obtain erythrocytes. The HA reaction was inhibited by specific antiserum. Some factors involved in the HA and HA-inhibition (HI) were investigated and standard HA and HI tests were established. HI antibody titers of individual chicken sera had a significant positive correlation with their neutralizing antibody titers.