However, much of the beginning on the Protecton has been covered and is repeated for the sake of completeness.
Antibodies function in serum in a concentration-dependent manner.
This means that there is a minimum threshold concentration of antibody that is functional and can cause the elimination of antigen. Recall that the structure of the repertoire is also influenced by how it has to function and remain under evolutionary selection. These are a little more subtle, but worth some thought. For example, recall that the germline repertoire has to be selected by pathogens that can only be ridded if the antibody is present in the high copy number B cells, and there are only as many of these P-antigens as there are V genes at the L and H chain loci. So, if there are 100 functional V L and 100 functional V H , there are 100 pathogens to select on them.