DEVELOPMENT OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY WITH MONOCLONAL-ANTIBODY FOR QUANTIFICATION OF HOMOVANILLIC IN HUMAN URINE SAMPLES

A monoclonal antibody to homovanillic acid (HVA) was prepared by synth esis of a HVA-protein conjugate (HVA-ovalbumin) as an immunogen, immun ization of mice, and the subsequent hybridization technique. Monoclona l antibodies were screened on the basis of sensitivity, specificity, a nd accuracy. An indirect ELISA was developed for quantification of HVA in human urine. The assay was characterized and shown to have high sp ecificity, with cross-reactivities to vanillylmandelic acid and normet anephrine at 0.18% and <0.1%, respectively. The assay coefficients of variation were <10% within the working range of 0.5-40 mg/L. Initial r esults from testing urine samples of patients with neuroblastoma and o ther diseases were validated by HPLC, suggesting that this ELISA metho d is a reliable and convenient system for quantification of HVA in uri ne and can be used in the mass screening of neuroblastoma in infants.