Androstenedione ELISA for serum or plasma 0.1-10 ng/ml Dialab

Androstendedione (also known as Δ4-androstenedione) is a steroid hormone produced in the adrenal glands and gonads as an intermediate step in the biochemical pathway that produces the androgen testosterone and the oestrogens oestrone and oestradiol. It is the common precursor of male and female sex hormones. Some androstenedione is also secreted into the plasma, and may be converted in peripheral tissues to testosterone and oestrogens. Androstenedione has relatively weak androgenic activity, estimated at ~20 % of testosterone. However, serum androstenedione levels often exceed testosterone in both normal and disease states. Secretion and production rates also exceed those of testosterone in women in whom significant extra-adrenal conversion of androstenedione to testosterone occurs. In premenopausal women both the adrenal glands and ovaries produce about half of the total androstenedione (about 3 mg/day). After menopause androstenedione production is approximately halved, primarily due to the reduction of steroid secreted by the ovaries. Nevertheless androstenedione is the principal steroid produced by the postmenopausal ovary. Measurement of serum androstenedione provides a useful marker of androgen biosynthesis. Elevated androstenedione levels have been demonstrated in virilising congenital adrenal hyperplasia, polycystic ovary syndrome, and in cases of hirsutism in women. Elevated serum androstenedione levels may also occur in adrenal and ovarian virilising tumours.
Female:
Follicular phase: 0.75-3.1 ng/ml
Luteinic phase: 0.94-3.2 ng/ml
Male: 0.60-2.7 ng/ml
This assay is intended for the quantitative determination of androstenedione in human serum or plasma for diagnostic use. This 96 well ELISA can provide up to 40 patient tests. Androstenedione in the sample competes with horseradish peroxidase (HRP) labelled androstenedione for binding onto the limited number of anti-androstenedione 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 androstenedione in the sample.
Kit contents:
Antibody coated Microtiter wells (Anti-androstenedione IgG): 12x8 well strips
Calibrator set (0.0; 0.1, 0.4, 1.2, 4.0, 10.0 ng/ml x 1.0ml)
Enzyme Conjugate (Anti-Androstenedione-HRP): 1x21ml
Substrate Solution (H₂O₂-TMB 0.25g/L): 1x15ml
Stop Solution (Sulphuric Acid 0.15mol/L): 1x11ml
Wash Buffer 10X (0.2M Phosphate buffer, pH 7.4, NaCl 160g/L, Tween-20 10g/L) : 1x50ml
Sample volume: 25µl 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 ng/mL
Sensitivity: 0.01ng/ml
Specificity: Androstenedione 100%, Testosterone < 0.001%, Epitestosterone 0.04%, 5 α-dihydrotestosterone 0.05%, DHEA 0.05%, Progesterone 0.007%
Store at 2-8°C.