What is Testosterone (LC-MS dried blood spot)?
Testosterone is the principal androgen in males, synthesised by Leydig cells under LH control, and in smaller amounts by the adrenal cortex and, in females, by the ovaries and peripheral conversion of precursors. It circulates mostly protein-bound (to SHBG and albumin), with 1–3 per cent free; dried blood spot reflects the total circulating pool equilibrated into capillary whole blood at the time of collection. Liquid chromatography tandem mass spectrometry delivers the specificity required to quantify testosterone reliably across the physiological range, including the low female and child concentrations where immunoassays often fail.