Determination of the Numeer of Fab₁ Pieces Which React with High Molecular Weight Antigens

Abstract

The sedimenting-droplet technique was used for the determination of the masses of immune Fab₁ pieces which may bind to antigenic sites on three haemocyanins. Similar experiments were conducted on three viruses which belong to the Tobamo group. It was calculated that 384 homologous Fab₁ pieces could bind to a molecule of the haemocyanin of Burnupena cincta and 950 homologous Fab₁ pieces to a virion of tobacco mosaic virus. By taking special precautions the number of undegraded antibody molecules which can bind to a Tobacco mosaic virus particle may be determined with the same technique.