DETECTION OF ANTISTREPTOLYSIN O-ANTIBODY - APPLICATION OF AN INITIAL RATE METHOD OF LATEX PIEZOELECTRIC IMMUNOASSAY

Latex piezoelectric immunoassay (LPEIA is a new latex immunoassay using a piezoelectric quartz crystal (Kurosawa et al. Chem. Pharm. Bull. 1990, 38, 1117). This assay requires no immobilization of antigen or antibody on an electrode surface of a piezoelectric crystal, while the immobilization is indispensable for ordinary immunoassays using a piezoelectric crystal as a microbalance. The present paper Improves a previous method (end-point analysis) by introducing the initial rate method using a batch cell; reduction if assay volume (1.2 mL) and shortening of assay time (2-3 min) were achieved. This assay was applied to the detection antistreptolysin O antibody (ASO) in serum. The frequency change was proportional to the ASO concentration up to 1040 IU mL-1, and the method had good sensitivity tor actual clinical application. The volume of serum required for the assay was 0.02 mL. Twenty-four clinical specimens were analyzed with this LPEIA, and the values obtained were compared with those obtained with a turbidimetric latex agglutination method. The correlation coefficient between these values was 0.950 (p < 0.01).