• Highly specific monoclonal antibody to ensure accuracy of reported result
  • Highly reproducible results
  • Suitable for measurement of a variety of sample types
  • Excellent correlation with existing automated testosterone assays
  • All reagents are ready to use
  • Part of a developing panel of steroid hormone assays

An automated assay for the quantitative determination of total testosterone in human serum or plasma. Measurement of testosterone are used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males; in females hirsutism (excessive hair) and virilisation (masculinisation) due to tumours, polycystic ovaries, and adrenogenital syndromes.

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).

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, 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