Question

1. When you witness a laboratory visual end-point of agglutination, you would view cells that are   ________________________

Answer 1

At the end point of agglutination reaction, cells are viewed as clumps. The agglutination reaction is hence better visualised because of the visible clumps, compared to precipitation reaction, where floccules or bands are formed.

In agglutination reaction, an insoluble antigen or particulate antigen combines with its antibody. This reaction occurs only when a large lattice is formed by alternating antigen and antibody. This happens at the zone of equivalence. When there is excess antibody(prozone) or excess antigen (postzone), lattice formation is inhibited. Another necessity is that the antigen should be bivalent or polyvalent and antibody should be bivalent.