LATEX IMMUNOASSAY OF BETA(2)-MICROGLOBULIN IN SERUM AND URINE

We have developed a nephelometric immunoassay for the quantitation of beta(2)-microglobulin in human serum and urine. The assay consists of incubating the diluted serum (400-fold) or urine (20-fold) samples for 12 min at room temperature with latex particles covalently coated wit h F(ab')(2) fragments of a polyclonal anti-beta(2)-microglobulin antis erum, and quantifying the change of light-scatter produced. The method is fully automated on the Behring nephelometer analyzer. The beta(2)- microglobulin standard curve extends from 0.3 to 21.1 mg/L for serum a nd from 16.5 to 1,050 mu g/L for urine samples. The coefficient of var iation ranged from 3.0 to 7.9%. No hemoglobin, bilirubin or Intralipid (R) interfered with the assay. Results of 68 serum samples correlated well (r > 0.994) with those obtained by a radioimmunoassay (RIA) metho d, a microparticle enzyme immunoassay, and a time-resolved fluoroimmun oassay procedure. Correlation coefficient between the latex immunoassa y and a RIA method was 0.937, calculated from the assay of 28 urine sa mples.