Specific Precipitation and Mouse Protection in Type I Antipneumococcus Sera

Abstract

Specific precipitation has long been known to occur in antipneumococcus sera showing marked protective power in mice (1), but it has been possible only recently to obtain indications of a parallel variation in these two properties. Thus Friedlander, Sobotka and Banzhaf (2) showed that the number of mouse protection units in certain Type I and Type II antipneumococcus sera varied in the same sense as the "precipitin index." In the preceding communication Zozaya, Boyer, and Clark (3) have shown that it is possible by means of the precipitin test to obtain within 2 hours numbers which agree excellently with the mouse protection units found in fifteen sera.The great advantages of a rapid in vitro test for the potency of antipneumococcus sera over the tedious, expensive, and often uncertain mouse protection test had led the writers to search for a possible relation between specific precipitation and mouse protection in Type I antipneumococcus sera on the basis of their recent quantitative study of the reaction between the specific polysaccharide of Type III pneumococcus and its homologous purified antibody (4) as well as on the basis of almost completed data on the corresponding Type I reaction. While this work has not resulted in so simple and rapid a routine test as that of Zozaya, Boyer, and Clark, the writers feel that it establishes on an experimentally verified and theoretically reasonable basis a definite parallel between maximum specific precipitation in Type I

The Precipitin Reaction Between Type Iii Pneumococcus Polysaccharide and Homologous Antibody

“…(Received for publication, December 27, 1934) Experiments were reported several years ago by the writers (1) leading to an absolute method for the determination of precipitins (2)(3)(4). It was originally thought that by following the usual immunological technique, namely incubation of precipitin reactions at 37°C.…”

Immunochemically-active cross-linked polystyrene preparations

“…Quantitative precipitin te8t. Antigen was determined by total N determinations on the specific precipitate according to the method of Heidelberger, Sia & Kendall (1930).…”

Studies on Immunizing Substances in Pneumococci

“…The methods used were the conventional ones for: nitrogen, glucose number, optical rotation, precipitin titer, immune precipitable nitrogen (Heidelberger, Sia and Kendall, 1930), and active immunity produced in mice. Two methods have been used for this last test, one varying the dose of antigen from 0.5 ml.…”