ABSTRACT
Stimulation of B lymphoid cells by antigen leads to the formation of immunoglobulin molecules (antibodies), which may enter into a number of different types of immunological and chemical reactions. These have been classified into (1) primary, (2) secondary, and (3) tertiary reactions. The
primary reaction
is the actual binding of antibody, via its Fab or antigen binding fragment, to its homologous antigen forming an antibody-antigen complex (Figure 8.1). After the two substances are brought into contact, their initial union takes place almost instantaneously (within milliseconds).
