Determination of beta(2)-microglobulin in human serum and urine by latex turbidimetry

A latex turbidimetric method for the measurement of beta(2)-microglobulin concentration in human serum or urine has been evaluated. The method is based on direct agglutination by beta(2)-microglobulin in human specimens of latex particles coated with an antibody against beta(2)-microglobulin. The agglutination is quantified by turbidimetry. The assay range is from 0.28 to 18 mg/L for serum and up to 3 mg/L for urine. The measured signal was linearly related to the beta(2)-microglobulin concentration for the serum assay but it was not for urine. The zone effect was out of physiological beta(2)-microglobulin concentration. Intra-assay and inter-assay precision were below 10%. Rheumatoid factor (up to 450 IU/mL), bilirubin (1 g/L) and lipaemia (20 g/L) did not interfere. Results of serum samples correlated well with those obtained by a radioimmunoassay method and a nephelometric immunoassay.