Estrone-3-Sulfate equine ELISA

>Background:Estrone-3-Sulfate (E3S) is the predominant conjugated estrogen during pregnancy. It is produced by the fetus, possibly in association with the endometrium in the pregnant mare. Different hormones are important for the complex events that occur during pregnancy in all mammals. In the mare these events include the maintenance of the corpus luteum function, formation of endometrial cups and development of secundary corpora lutea. Progesterone and PMSG (Pregnant Mare Serum Gonadotropine, eCG) and also free Estrogens, e.g. Estrone, are associated with these processes. It has been shown, that Estrone is rapidly conjugated after secretion and the ratio between conjugated and unconjugated estrogens is 100:1 in mare serum. The conjugated estrogenes, especially Estrone-3-Sulfate, provide the opportunity to improve the accuracy of pregnancy diagnosis, to monitor the pregnancy and to distinguish whether the fetal development is normal or impaired. The diagnosis of embryonic death is usually made by using techniques of palpation of the uterus per rectum or ultrasound echography. The determination of Estrone-3-Sulfate is an aid in the non-invasive diagnosis which allows monitoring of the feto-placental unit during pregnancy. Only in mares with normal fetal development the values of Estrone-3-Sulfate show a tremendous increase between day 75 and 100 of gestation.

Description:
The Estrone-3-Sulfate equine ELISA test kit is a solid phase enzyme immunoassay (ELISA) in the microplate format, designed for the quantitative measurement of Estrone-3-Sulfate. The microplate is coated with a polyclonal antibody specific for Estrone-3-Sulfate. Calibrators and samples as well as a biotin-labeled Estrone-3-Sulfate are pipetted into the antibody coated microplate. During one hour incubation the Estrone-3-Sulfate of the calibrator/sample competes with the biotin-labeled Estrone-3-Sulfate for the binding sites of the antibody fixed on the inner surface of the wells. Afterwards, horseradish peroxidase-labeled streptavidine is added. During a 30 minutes incubation, this enzyme-labeled streptavidine binds to the biotinylated Estrone-3-Sulfate. All wells are washed to remove excess of non-bound enzyme-labeled streptavidine. A chromogenic substrate, TMB (3,3',5,5'-Tetra-Methyl-Benzidine), is added to all wells. During a 30 minutes incubation, the substrate is converted to a colored end product (blue) by the fixed enzyme. Enzyme reaction is stopped by dispensing of hydrochloric acid as stop solution (change from blue to yellow). The color intensity is inversely related to the concentration of Estrone-3-Sulfate present in the sample. The optical density of the color solution is measured with a microplate reader at 450 nm.

Product features:
The kit contains reagents for 96 determinations;
Microtiter plate consisting of 12x8 (breakapart);
Microtiter plate reader at 450 nm;
Analytical sensitivity: 0,424 ng/mL.