The Precipitin Reaction of Antipneumococcus Sera

Abstract

The precipitin indices for a number of monovalent and polyvalent antipneumococcus sera were determined under known conditions, and found to vary as did the number of protective units. The ratio precipitin index/protective units in monovalent sera was found to lie between 2.8 and 4.8 for Type I and to be about ten times greater for Type III. Lower values were found in polyvalent horses and when mixing heterologous monovalent sera with each other. The influence of the duration of treatment upon the quotient was studied. Several refined and concentrated preparations showed a relative increase in precipitin activity.

Specific Precipitation and Mouse Protection in Type I Antipneumococcus Sera

“…(Received for publication, June 17, 1930) 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.…”