BioVision's PGE1 ELISA kit uses the Competitive-ELISA principle. The micro ELISA plate provided in this kit has been pre-coated with PGE1. During the reaction, PGE1 in the sample or standard competes with a fixed amount of PGE1 on the solid phase supporter for sites on the Biotinylated Detection Ab specific to PGE1. Excess conjugate and unbound sample or standard are washed from the plate, and Avidin conjugated to Horseradish Peroxidase(HRP) are added to each microplate well and incubated. Then a TMB substrate solution is added to each well. The enzyme-substrate reaction is terminated by the addition of stop solution and the color change is measured spectrophotometrically at a wavelength of 450 nm