Testosterone is a steroid hormone that is primarily produced by the testes in males and the ovaries in females. The determination of testosterone levels is crucial in the assessment of hypogonadal states, tumor detection, and in monitoring hormone replacement therapy. The FastPack® IP Testo Immunoassay is a chemiluminescent immunoassay for the in-vitro quantitative determination of total testosterone in human serum and plasma. Designed for use with the FastPack® IP System.