A Study of the Reliability of Complement Fixation As a Method of Measuring the Activities of Sera of High, Medium, and Low Antibody Titer

摘要

The relationships between complement-fixing capacity, combining activity with homologous type-specific carbohydrate, and precipitative antibody-nitrogen content have been studied for antipneumococcus rabbit sera of high, medium, and low titer. Methods of estimating antibody-nitrogen values from complement-fixation titers have been developed in which these numerical relationships are applied.As a means of defining the complement-fixing capacity of a standard quantity of antipneumococcus rabbit serum, with antigen, the expression , which represents the total fixation corrected for change in the hemolytic activity of complement during incubation, was judged on the basis of its closer relationship to W 0.05, the maximally reactive dose of antigen, to be more accurate than either [(S + A)′ - 1], the total fixation stated in “arbitrary” units, or , the total fixation corrected for differences in the anticomplementary activity of 0.05 ml of serum.![Figure][1]/img![Figure][1]/img [1]: pending:yes