Amplifex™ Keto Reagent; BSA, Bovine Serum Albumin; CDC certification; CDC, Center for Disease Control; CE, Collision Energy; CLSI, Clinical and Laboratory Standards Institute; CUR, Curtain Gas; CV, Coefficient of variation; CXP, Cell Exit Potential; Clinical assay; DP, Declustering Potential; Derivatization; ESI, Electrospray Ionization; ESI-LC-MS/MS; F, Female; Female and pediatric samples; HoSt certification program; HoSt, Hormone Standardization; IS, Internal Standard; IVD, In Vitro Diagnostic; K2EDTA; K2EDTA, Ethylenediaminetetraacetic acid dipotassium; LC-MS/MS, Liquid Chromatography-Mass Spectrometer (tandem); LLOQ, Lower Limit of Quantitation; Li, Lithium; Li-Heparin (LH); M, Male; MD, Medical Device; Matched patient sample; Max, Maximum; MeOH, Methanol; Min., Minimum; NIST, National Institute of Standards and Technology; Oxime; Plasma; Q, Quarter; S/N, Signal to Noise; Serum; Total testosterone; eV, electronvolt