Evaluation of time-resolved fluoroimmunoassay with Eu-labelled protein-A for serum progesterone

Progesterone has been assayed in several serum samples by a time-resolved fluoroimmunoassay (TR-FIA). The solid phase was 11 alpha-hydroxyprogesterone hemisuccinate bound covalently to ovalbumin and adsorbed on wells of polystyrene. The assay was based on competitive reaction of solid phase-bound hormone and samples with specific antibody labelled in situ with protein-A prelabelled with europium. The bound Eu was dissociated from the solid phase by an enhancement solution and measured by time-resolved fluorometry. The coefficient of correlation between TR-FIA and RIA was 0.97.