Description

The Diagnostic Automation Estriol ELISA kit is intended for the quantitative determination of Estriol. Estriol (also oestriol) is one of the three main estrogens produced by the human body. It is a competitive immunoenzymatic colorimetric method for quantitative determination of Free Estriol concentration in serum and plasma. It is only produced in significant amounts during pregnancy as it is made by the fetus. During pregnancy the production of estriol depends on an intact maternal-placental-fetal unit. Fetal-placental production of estriol leads to a progressive rise in maternal circulating levels reaching a late-gestational peak several orders of magnitude greater than non-pregnant levels.



In the maternal circulation, estriol undergoes rapid conjugation in the liver followed by urinary excretion with a half-life of ~20 minutes. Since normal estriol production depends on an intact maternal-placental-fetal circulation and functional fetal metabolism, maternal estriol levels have been used to monitor fetal status during pregnancy, particularly during the third trimester. DHEA is produced by the adrenal cortex of the fetus; this is converted to estriol by the placenta. If levels are abnormally low in a pregnant woman, this may indicate a problem with the development in the child. Levels of estriol in non-pregnant women do not change much after menopause, and levels are not significantly different from levels in men.

Free Estriol (antigen) in the sample competes with horseradish-peroxidase Estriol (enzyme-labeled-antigen) for binding onto the limited number of anti Estriol (antibody) sites on the microplates (solid phase). After incubation, the bound/free separation is performed by a simple solid-phase washing. The enzyme substrate (H2O2) and the TMB-Sustrate (TMB) are added. After an appropriate time has elapsed for maximum colour development, the enzyme reaction is stopped and the absorbance is determined. Free Estriol concentration in the sample is calculated based on a series of standard. The colour intensity is inversely proportional to the Free Estriol concentration in the sample.