A rapid and sensitive immunosorbent assay for urinary albumin

We describe a fast, simple and sensitive microtiter scale competitive ELISA for the determination of urinary albumin. All reagents are commercially available. In the standard procedure, a minimum concentration of 0.8 mg albumin/L can be measured, although, applying another dilution, 0.04 mg/L can be detected. Within-batch coefficient of variation was 6.9% and 5.6% (at 1:20 and 1:50 dilution, respectively); between-batch variation was 8.6% and 5.6% respectively. The influence of urine pH and other urine components is minimised in the assay diluting with a casein-containing buffer.