25-OH Vitamin D (total)
The DRG 25-OH Vitamin D (total) ELISA is an enzyme immunoassay for measurement of total 25-OH Vitamin D (Vitamin D2 and Vitamin D3) in serum and plasma.
Vitamin D is a steroid hormone involved in the intestinal absorption of calcium and the regulation of calcium homeostasis. The two major forms of Vitamin D, named Vitamin D3 (cholecalciferol) and Vitamin D2 (ergocalciferol), have isomeric structures, but D2 is supposed to be less active than D3 1.
The 25-OH Vitamin D total ELISA Kit is a solid phase enzyme-linked immunosorbent assay (ELISA), based on the principle of competitive binding. In the first step, samples have to be pretreated in separate vials with denaturation buffer to extract the analyte, since most circulating 25-OH Vit D is bound to VDBP in vivo. After neutralization, biotinylated 25-OH Vitamin D (enzyme conjugate) and peroxidase-labeled streptavidin- (enzyme complex) are added. After careful mixing, the solution is transferred to the wells of the microtiter plate. Endogenous 25-OH Vitamin D of a sample competes with a 25-OH Vitamin-D3-biotin conjugate for binding to the VDBG that is immobilized on the plate. Binding of 25-OH Vitamin Dbiotin is detected by peroxidase-labeled streptavidin. Incubation is followed by a washing step to remove unbound components. The color reaction is started by addition enzyme substrate and stopped after a defined time. The colour intensity is inversely proportional to the concentration of 25-OH Vitamin D in the sample.
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