Quantitative Studies of Lipid-Soluble Tissue Antigens as Exemplified by the Wassermann Antigen-Antibody System

Abstract

Summary: An analytic procedure is described for the estimation of the Wassermann antibody in human and rabbit sera in absolute weight units. The quantitative ninhydrin reaction was applied to the estimation of antibody uptake by suspensions of cardiolipin, lecithin and cholesterol. The uncertainty introduced in these analyses by the failure to decomplement the sera has been discussed. The reaction curves obtained with Wassermann antibody and cardiolipin can be described by the Heidelberger-Kendall equation as applied to quantitative precipitation or agglutination. Calculations based on the values for precipitable antibody N indicate that standard serologic tests for syphilis may detect as little as 0.014 μg of Wassermann antibody N. Data are also given with respect to the heat lability of the Wassermann antibody and the inhibitory effect of normal human serum on aggregate formation by this antibody with suspensions containing cholesterol, lecithin and cardiolipin.