Interpretation of results
 In the wells where antibodies are present there will be haemagglutination 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 haemagglutination inhibition. Use the control well as a point of comparison. Be consistent in determining the endpoint.