Antibodies

IgG

The dominant, long-lived antibody responsible for opsonization, neutralization, ADCC, and the only class crossing the placenta.

IgA

Mucosal surface antibody that neutralizes pathogens before they penetrate tissue.

IgM

First responder antibody that excels at complement activation and agglutination.

IgD

Primarily a surface receptor on naive B cells with largely unclear function.

IgE

Triggers mast cell degranulation driving allergic responses, with a physiological role against parasites.