A METHOD FOR THE QUANTITATIVE MEASUREMENT OF AGGLUTININ NITROGEN IN ANTISERA TO HEMOPHILUS PERTUSSIS, PHASE I

Abstract

A method for the measurement, in weight units, of the agglutinin nitrogen in antisera to Hemophilus pertussis, Phase I, is described. The procedure and techniques are essentially the same as those first published by Heidelberger and Kabat for the measurement of agglutinin nitrogen in antipneumococcal sera. However, it was found that unusually large amounts of bacterial nitrogen were required to absorb pertussis agglutinins completely, even when the antibodycontent of the antisera was low. The accuracy of this method is limited to ± 1-2%, the error involved in the Kjeldahl procedure for measuring nitrogen. Thus, the large amounts of bacterial nitrogen necessary for absorption and the relatively low agglutinin nitrogen content of the antisera indicated that the results of one, or at the most two, absorptions be used to calculate values with some meaning in terms of quantitative analytical chemistry. Analysis of an unknown antiserum can now be accomplished in one or two absorptions if 1.0 ml. volumes of appropriate dilutions of serum are absorbed with approximately 2 mgm. of bacterial nitrogen. The antibody content is calculated from the dilution of serum which was completely absorbed.