Detection of Virus antibodies by Hemagglutination Inhibition (HI) assay
In the wells where antibodies are present there will be hemagglutination inhibition. The red blood cells will settle as a button.
In the wells where antibodies are absent, the red blood cells will agglutinate.
The end point of the titration is the well that shows complete haemagglutination inhibition.
Sometimes it is not easy to determine. Look at the size of the button as an indication of the degree of hemagglutination inhibition. Use the control well as a point of comparison. Be consistent in determining the endpoint.
Detection of Virus antibodies by Neutralization assays
Interpretation of results
Other methods for Detection of Virus antibodies
There several other serologic methods which are used for detecting virus antibodies .
These methods are not covered under this topic but I will list them and they might be covered elsewhere. These methods include: Complement fixation tests (CFT), Enzyme immunoassays (Enzyme linked immunosorbent assay (ELISA)), Immunofluorescence techniques (IF), Counter-immunoelectrophoresis, Radioimmunoassays (RIA), Western Blot (WB), RIBA, line immunoassays and Particle agglutination.