DEVELOPMENT OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR 2,3-DINOR-6-KETO-PROSTAGLANDIN F1-ALPHA IN URINE USING A MONOCLONAL-ANTIBODY

Objectives: To develop and validate an enzyme-linked immunosorbent ass ay (ELISA) for measurement of urinary 2,3-diner-6-keto-prostaglandin F -1 alpha (2,3D6KPGF(1 alpha)) using a monoclonal antibody and a horser adish peroxidase-linked antigen. Design and Methods: Assay validation included optimization of the standard curve, antibody cross-reactivity , accuracy and imprecision studies together with preliminary measureme nt of clinical samples. Results: Optimal conditions of the standard cu rve (0.078-10.0 mu g/L) used 2 mg/L of antibody and 3 mu g/L of peroxi dase conjugate in each well, at pH 7.2. The coefficient of variation o f various concentrations of the standard curve averaged 6.8%. Antibody cross-reactivity was <0.01% for related prostanoids. Recovery of know n amounts (0.1-5.0 mu g/L) of 2,3D6KPGF(1 alpha) added to an urinary s ample was 101.2 +/- 6.3%. Imprecision studies with non-pregnant (0.24 mu g/L) and pregnant (2.5 mu g/L) samples displayed an intraassay vari ability of 8.9 and 9.9%, and an interassay variability of 9.6 and 10.0 %, respectively. Urinary measurements in the non-pregnant-and pregnant states were similar to those previously reported. An apparent decreas ed concentration was observed early in pregnancy in future preeclampsi a. Conclusion: With similar precision and validity, our assay method i s time- and cost-saving. Preliminary urinary measurements show that th is analyte may be of interest as an early marker for preeclampsia.