Dehydroepiandrosterone-Sulphate (DHEA-S) ELISA for serum or plasma 0.1-10.0 µg/ml Dialab

Dehydroepiandrosterone sulphate (DHEA-S), is a natural steroid hormone derived from the enzymatic conversion of DHEA in the adrenal and extra adrenal tissues. DHEA-S is also produced in the gonads, adipose tissue and the brain. It is the most abundant hormone in the human body and it is the precursor of all sex steroids. As most DHEA-S is produced by the zona reticularis of the adrenal gland, it is argues that there is a role in the immune system and stress response. DHEA-S may have additional biological roles. Its production in the brain suggests that it also has a role as a neuro-steroid. Measurement of serum DHEA-S is a useful marker of adrenal androgen synthesis. Abnormally low levels may occur and have been reported in hypoadrenalism, while elevated levels occur in several conditions, e.g. virilising adrenal adenoma and carcinoma, 21-hydroxylase and 3β-hydroxysteroid dehydrogenase deficiencies and in some cases of female hirsutism. Women with polycystic ovary syndrome tend to have normal or mildly elevated levels of DHEA-S. As very little DHEA-S is produced by the gonads, measurement of DHEA-S levels may aid in the localisation of androgen source in virilising conditions. DHEA-S levels show no diurnal variation.
Women µg/ml Men µg/ml
Newborns 0.9-1.8 0.9-1.8
Before puberty 0.25-1.0 0.25-1.0
Adults 0.9-3.6 0.9-3.6
After menopause <0.25-1.0 N/A
Pregnancy 0.25-1.8 N/A

This assay is intended for the quantitative determination of DHEA-S in human serum or plasma for diagnostic use. This 96 well ELISA can provide up to 40 patient tests. DHEA-S in the sample competes with horseradish peroxidase (HRP) labelled DHEA-S for binding onto the limited number of anti-DHEA-S sites coated on the microplate. After incubation, the bound/free separation is performed by a simple- solid-phase washing. The enzyme in the bound-fraction reacts with the substrate to develop a blue colour which changes to yellow on addition of the stop solution. The colour intensity, as determined by reading absorbance at 450nm, is inversely proportional to the concentration of DHEA-S in the sample.
Antibody coated Microtiter wells (Anti-DHEA-S IgG): 12x8 well strips
Calibrator set (0.0, 0.1, 0.4, 1.0, 4.0, 10.0 µg/ml x 1.0ml)
DHEA-S Control: 1x1ml
Sample Diluent 5X (HEPES 187mM, pH 7.5, BSA 0.5g.l): 1x20ml
Enzyme Conjugate (Anti-DHEA-S-HRP): 1x12ml
Substrate Solution (H₂O₂-TMB 0.26g/L): 1x15ml
Stop Solution (Sulphuric Acid 0.15mol/L): 1x15ml

Sample volume: 30µl human serum or plasma to be run in duplicate
Incubation time: 75 minutes (60 min at room temperature, 15 min in the dark at room temperature)
Measuring range: 0.1-10.0 µg/mL
Sensitivity: 0.03 µg/ml
Specificity: DHEA-S 90%, DHEA 100%, Androsterone-S-NA 48%, Androstenedione 20%, Testosterone 0.01%, Progesterone < 0.01%, Oestrone 0.01%, Cortisol 0.001%. Cholesterol 0.001%
Store at 2-8°C.