Immunonephelometric assay of human apolipoprotein AI

We report an immunonephelometric assay for apolipoprotein AI, which involves use of a laser nephelometer and an antiserum prepared in our laboratory. Coefficients of variation were 2.5% within-run, 6.3% between-run. Several types of manipulation of the samples (heating, delipidation, dissociation with urea), reportedly necessary for accurate determinations by radioimmunoassay or gel diffusion immunoassay, did not substantially affect results obtained with our technique. The assay is sensitive, reproducible, and simple, and appears suitable for routine use.