The Precipitation Reaction. Experiments with an Antiserum Containing Two Antibodies

Abstract

Ofthe chemical structure of antibodies little or nothing is known. It is generally held that the specific properties of an antiserum are closely associated with the globulin fraction. An antiserum may be distinguished from a normal serum by the precipitation of some of its globulins in the presence of the homologous antigen. The formation of a precipitate in a mixture of antigen and antiserum may be explained in either of two ways: (1) The reaction which occurs when antigen is added to antiserum may produce such physical changes in the mixture that normal globulin is precipitated. The reaction takes place between two specific substances, the antigen and the antibody, and is rendered visible by the presence of a non-specific globulin which plays the part of an indicator. (2) Or we may suppose that in the process of immunisation the antigen produces a specific alteration in the structure of the globulin. That is to say, the antibody is a specifically altered globulin, which has undergone some change in its molecular structure, in virtue of which it can react and combine with the homologous antigen.

The Precipitation Reaction: Experiments on Multiple Zones

“…The preparation of the antisera used in the present work was described by Dean, Taylor and Adair (1935). Titrations have been performed by the method of optimal proportions, in which a wide range of antigen dilutions, each in a volume of 1 c.c., is arranged, so that the amount of antigen is halved in successive tubes.…”

Serologic Demonstration of Dual Specificity of Rabbit Bivalent Hybrid Antibody

“…Milgrom et al (15) have described rheumatoid factors (macroglobulins) of mixed specificity directed against rabbit and human gamma globulins but these results are probably entirely explainable on the basis of antigenic determinants common to both rabbit and human gamma globulin. However, attempts to demonstrate the presence of 7S antibody of dual specificity in rabbits hyperimmunized with two antigens have been uniformly unsuccessful (22)(23)(24)(25)(26)(27). Experiments of the types reported here should be useful as a model for determining whether very small amounts of hybrid 7S molecules are iormed in ~o.…”

Some Properties of a Thermolabile Antigen of Erysipelothrix rhusiopathiae

“…It is generally believed (see e.g. Dean, Taylor & Adair, 1935), that the components of a mixture of antigens stimulate antibody production independently of each other. On the other hand, following the work of Heidelberger & Kendal (1934), it has been suggested that a single antigen molecule, possessing more than one kind of reactive group, can give rise to antibody molecules specific for one group only, for some, or, for all the groups (Marrack, 1938).…”