Properties of Antibodies
Linus Pauling
Sept. 26, 1941
During recent years there has been developed through the work of many investigations (Landsteiner, Heidelberger, Horrowitz, Marrack, Stuart Mudd, and others) a general idea of the nature of immunological process.  This has been extended into a detailed picture of the structure and process of formation of antibodies by the application of our present knowledge of the structure of molecules and the nature of intermolecular interactions.
My collaborators, Dr. Dan
[END PAGE ONE]
[BEGIN PAGE TWO]
Campbell, Dr. David Pressman, and Mr. Carol Iheda[?], and I have now obtained quantitative experimental results along several lines which support this picture.
We have found that trivalent and trivalent haptenes, similar to those used by Landsteiner and van der Scheer, give precipitates with antibody-antigen molecular ratio close to 1.  This and other results support the postulate that antibodies effective in precipitin reaction are bivalent.
Precipitates have also been obtained between antiserum
[END PAGE TWO]
[BEGIN PAGE THREE]
and azoproteins with an average of only two haptenes per molecule.  It has also been found that haptenes can be attached by azo groups to erythrocytes without hemolyzing the cells, and agglutination of cells has been produced with only about fifty haptenes per cell.
It was predicted that antibodies could be manufactured outside the animal by
[END PAGE THREE]
[BEGIN PAGE FOUR]
a process of denaturing a protein and slowly denaturing it in the presence of antigen.  This has now been done, with use of a variety of denaturing agents.  The dye methyl blue and an azo dye containing atoxyl have been used as antigens.  The protein solutions obtained have various properties characteristic of antibodies, including specificity to the antigen used and solubility
[END PAGE FOUR]
[BEGIN PAGE FIVE]
of antigen-antibody precipitate in excess of antigen or of haptene.