ABSTRACT
Antibodies are glycoproteins that bind antigens with high specificity and affinity (they hold on tightly). They are molecules, originally identified in the serum, which are also referred to as “immunoglobulins,” a term often used interchangeably with antibodies. In humans there are five chemically and physically distinct classes of antibodies (IgG, IgA, IgM, IgD, and IgE).
