Enzyme-linked immunosorbent assay of antibodies in human sera to streptococcal DNase B

An ELISA method for determining the streptococcal anti--DNase B titers in human sera is presented. The details of this technique, a method for converting A493 readings into titers, and a standardization procedure are discussed. Anti--DNase B titers of 20 sera determined by ELISA were compared with titers determined by the microtechnique. A correlation coefficient of 0.96 between the two methods was obtained. The reproducibility of the ELISA method was established by comparing titers obtained from two separate determinations on the 20 sera. Twenty-four pairs of acute and convalescent sera were assayed for anti--DNase B titers by both ELISA and microtechnique to compare the ability of the two techniques to identify significant titer rises. The ELISA was as specific and possibly more sensitive than the microtechnique in identifying significant anti--DNase B titer rises. This ELISA method is simple and rapid and has the potential for automation.