Molecular and Immunological Diagnostic Techniques of Medical Viruses

Figure 7

Hemagglutination inhibition assay of avian influenza virus. When the RBCs are alone, they will settle in the bottom of the well. Where specific antibody is absent in the clinical specimen, the viral hemagglutinin is free to agglutinate the RBCs. The HI titer of S1–S5 is 2¹⁰. Abbreviations: R, RBCs only; V + R, virus and RBCs; PC, positive control; S, sample (unpublished data).