VACMUNE®: biosyn's immunocyanin as carrier protein in vaccine manufacture, antibody production and other uses
Basic to the humoral immune response is the formation of antibodies or protein molecules, defined as an 'immunoglobulin capable of specific combination with the antigen that caused its production in the susceptible animal.'
Antigens are traditionally defined as any substance that, when introduced parenterally into an animal, will cause the production of antibodies and will react specifically with the antibodies in vitro, which in turn is the basis of a number of immunological assays.
Such antigens are macromolecules (MW >10,000 Da) with a high degree of internal chemical complexity. Antibodies are not produced against one's own own molecules or against low molecular weight molecules (< 10,000 Da).
Haptens are low molecular weight molecules that are non-antigenic and cannot stimulate an immune response by themselves when introduced into the body as a foreign substance. An immune response can be elicited against such haptens when they are combined, chemically or physically, with large protein molecules which basically act as a carrier. Such protein molecules are therefore called, appropriately, carrier molecules.