Free Testosterone ELISA

Intended Purpose
The Free Testosterone ELISA is intended for the measurement of free testosterone in serum in adults. Measurement of free testosterone is an aid in diagnosis of hormone imbalance that results in various clinical conditions like hypogonadism (androgen deficiency) in men and hypergonadism (excess of androgen hormones) e.g. polycystic ovaries in women. The Free Testosterone ELISA is a solid phase enzyme-linked immunosorbent assay (ELISA), based on the principle of competitive binding and measured on an absorbance reader. The assay is semi-automated requiring general purpose laboratory instruments and consumables such as absorbance microplate reader/washer, vortexer and pipettes to execute the test. The assay is adaptable by laboratory personnel to automate on open ELISA-based liquid handler platforms like EVOlyzer or DSX; however, the programming of the steps and timing required by the manual kit assay test instructions must be strictly adhered to and verified by the laboratory. Test results may be calculated from a standard curve and compared to laboratory-established reference ranges from healthy adults (i.e. normal ranges). The test kit is intended for professional laboratory use by trained personnel. The test kit is not for home or layperson use. The Free Testosterone ELISA is NOT intended for point-of-care settings.

Clinical significance
Testosterone is a pleiotropic hormone [1], meaning it affects different phenotypes and plays an important role in the human body. It is a C19-steroid and the most effective natural hormone in the family of androgens. Testosterone in men is produced by the testes as well minimally by the adrenal cortex. In women testosterone derives from the production in the adrenal cortex and ovaries, accounting for 50 % of testosterone, while the remainder is produced from peripheral tissues such as bone, breast, muscle, and fat. [2] Like other steroid hormones, testosterone concentrations follow a diurnal rhythm, with testosterone levels peaking in the morning and declining during the day. [3] Roughly 1 - 5 % of free testosterone are present in serum of healthy individuals with 38 % albumin-bound testosterone, and 60 % sex hormone-binding globulin (SHBG)-bound testosterone; where the latter two are typically unable to enter the intracellular environment and exert their biochemical effects [4; 5]. To determine the level of testosterone, it is relevant to measure the free fraction [7] because it is biologically active [6] and it can be performed in bodily fluids like plasma or serum. Measuring testosterone plays a vital role in the diagnosis of different endocrine disorders. [1] An increased testosterone level can be due to testicular or pituitary abnormalities [7] or androgen abuse in men. A decline in hormone production including testosterone can be observed in aging men who experience a variety of symptoms with declining testosterone levels e.g. thinning hair, loss of vigor or sexual dysfunction. [8] Measurement in women is applied as an aid to diagnose clinical hypogonadism and to help diagnose hyperandrogenic states e.g., hirsutism, ovarian failure [9] and infant congenital adrenal hyperplasia [10], ovarian or adrenal neoplasm, polycystic ovarian syndrome. [11; 12]

For concrete data please consult the Instruction for Use in the download box on the top right side.