| Abbreviation | Name | Description |
|---|---|---|
| HA | Hemagglutination | (HA) is a technique for detecting specific antibodies which, when present, will cause antigen-coated reagent erythrocytes to agglutinate. Crude quantitation of the antibodies can be achieved by performing a serial dilution of the patient serum and noting the highest dilution (titer) at which agglutination is still present. |