Polyclonal antibody
Polyclonal antibodies are mixtures of different antibodies that are obtained from the serum of immunized animals (mostly goats, rabbits, mice or rats). By adsorption on an antigen in an affinity chromatography , all antibodies against the different epitopes of an antigen can be purified together, although the antibodies were produced by different B cells .
In contrast, a monoclonal antibody is only produced from clones of a single B cell and is therefore only directed against a single epitope of a protein. In contrast to monoclonal antibodies, polyclonal antibodies are a natural mixture.
Manufacturing
In practice, in a similar way to active immunization in humans (see vaccination ), an animal is injected with an antigen , e.g. B. a viral protein or its gene in an expression vector. The animal then forms specific antibodies against the foreign protein in an immune reaction . The result is a natural mixture of several different antibodies that bind with different affinity to one of the different epitopes of this antigen. The sum of the binding energies between polyclonal antibodies and all epitopes of an antigen is called avidity .
For the artificial production of monoclonal antibodies, polyclonal B cells are required, from which individual monoclonal antibodies can be selected after fusion to a hybridoma or viral immortalization of the B cells (see production of monoclonal antibodies ).
In rare cases it happens that polyclonal antibodies are directed against only one epitope.
literature
- Charles Janeway , Paul Travers, Mark Walport, Mark Shlomchik: Immunology. 5th edition, Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-1079-7 ; Online version in English , 5th edition, 2001.
Individual evidence
- ↑ 2.1 Polyclonal antibodies on pathologie-Online
- ↑ a b K. Heilmann, K. Messerschmidt, P. Holzlöhner: Monoclonal antibodies - production and use . In: Biospektrum (18), February 2012, 167-169; doi : 10.1007 / s12268-012-0160-5 .