Free Testosterone ELISA

Key Features and Values

– Same sample type can be used across all assays to simplify inclusion into routine serology work-up
– Ready to use reagents reduces hands-on time for assay preparation
– Long shelf life cost-effective solution by reducing wastage due to expired kits
– Suitable for inclusion on automated plate systems simplifies scale-up of test volume
– Supported by a complete panel of assays for supporting treatment monitoring of several forms of hormonal dysfunctions

Product Description

Competitive immunoenzymatic colorimetric method for the quantitative determination of Free Testosterone concentration in human serum or plasma. Second generation kit.
Free Testosterone ELISA kit is intended for laboratory use only.

Scientific Description
Testosterone (17β-OH-4-androstene-3-one) has a molecular weight of 288 Daltons and is considered to be the principle androgen found in circulation of mature male mammals1. In males it is synthesised and secreted by the Leydig cells located in the interstitium of the testis, and in females testosterone is produced in various locations such as the ovaries, adrenal gland and peripheral tissues, with additional production due to inter-conversion from other steroid hormones.  The secretion of testosterone is regulated by luteinising hormone (LH).  Testosterone is found in circulation predominantly linked to carrier proteins, the most common of which being sex-hormone binding protein (SHBG).
Testosterone plays a key part in the development of reproductive tissues and secondary sex characteristics in men.  There is an observed and well documented circadian variation of testosterone levels in men with the circulating concentration being higher in the morning and declining throughout the day2.  Testosterone levels also decline in ageing males (andropause) is often associated with loss of muscle and bone mass, leading to osteoporosis, loss of libido, erectile dysfunction, depression and impaired cognitive function3.
In males elevated levels of testosterone are associated with, but not limited to, early (precocious) puberty, congenital adrenal hyperplasia (CAH), androgen insensitivity syndrome (AIS), steroid use and testicular or adrenal tumours; whereas the major causes of supressed levels in males include Klinefelter’s syndrome, testicular damage, pituitary disorders etc.
In females of all ages, elevated testosterone levels can be associated with a variety of virilising conditions including adrenal tumours and polycystic ovarian syndrome (PCOS).
The recent increase in testosterone measurements in the last years have focussed attention on the need for an accurate assessment of Free Testosterone levels for males with suspected androgen deficiency and to support dosing of testosterone replacement therapy4. Therefore, measurement of free testosterone can be considered useful in the diagnosis of several conditions including androgen deficiency in men and androgen excess in women5.  Assessment of free testosterone levels may prove beneficial6 and may avoid an incorrect diagnosis of hypogonadism in cases when low concentrations of total testosterone are determined and alterations of SHBG are suspected.



1. Jamerson JL, de Kretser D, Marshall JC and De Groot LJ. Endocrinology – adult and pediatric 6th edition. pp 368-374
2. Brambilla DJ, Matsumoto AM, Araujo AB and McKinlay JB. The Effect of Diurnal Variation on Clinical Measurement of Serum Testosterone and Other Sex Hormone Levels in Men. J Clin Endocrinol Metab. 2009 Mar; 94(3): 907–913
3. Rajfer J. Decreased Testosterone in the Aging Male. Rev Urol. 2003;5(suppl 1):S1–S2.
4. Goldman AL, Bhasin S, Wu FCW, Krishna M, Matsumoto AM, Jasuja R.  A Reappraisal of Testosterone’s Binding in Circulation: Physiological and Clinical Implications.  Endocr Rev. 2017 Aug 1;38(4):302-324
5. Shea JL, Wong PY, Chen Y. Free testosterone: clinical utility and important analytical aspects of measurement. Adv Clin Chem. 2014;63:59-84.
6. Diver MJ. Analytical and physiological factors affecting the interpretation of serum testosterone concentration in men. Ann Clin Biochem. 2006 Jan;43(Pt 1):3-12.


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Code: DKO015
Clinical Area:
Incubation: 60+15 min
Sensitivity: N/A
Specificity: N/A
Classification: IVD, CE
Number of Tests: 96
Sample Type: Serum/Plasma
Sample Volume: 20 μL
Assay Range: 0.2 - 100 pg/mL