Testosterone, Free (Direct) With Total Testosterone, LC/MS-MS

Additional Information:

UFHPL Epic order code: LAB21017301


Catrou PG, Beeler MF. Disorders of gonadal and fetoplacal function. Interpretations in Clinical Chemistry. 2nd ed. Chicago, Ill: America Society of Clinical Pathologists;1983:76-82.

Green PJ, Yucis MJ. Free-testosterone determinations by ultrafiltration and comparison with dialysis. Clin Chem. 1982 May; 28(5):1237-1238. PubMed 7074915

Ruutiainen K, Sannikka E, Santti R, Erkkola R, Adlercreutz H. Salivary testosterone in hirsutism: Correlations with serum testosterone and the degree of hair growth. J Clin Endocrinol Metab. 1987 May; 64(5):1015-1020. PubMed 3558722

Vittek J, L’Hommedieu DG, Gordon GG, Rappaport SC, Southren AL. Direct radioimmunoassay (RIA) of salivary testosterone: Correlation with free and total serum testosterone. Life Sci. 1985 Aug 26; 37(8):711-716. PubMed 4021735

Vlahos I, MacMahon W, Sgoutas D, Bowers W, Thompson J, Trawick W. An improved ultrafiltration method for determining free testosterone in serum. Clin Chem. 1982 Nov; 28(11):2286-2291. PubMed 7127776

Wheeler JE, Rudy FR. The tests, paratesticular structures, and male external genitalia. In: Silverburg SG, ed. Principles and Practice of Surgical Pathology. 2nd ed, vol 2. New York, NY: Churchill Livingstone;1990:1531-1585.

CPT Code(s):

84403, 84402

Specimen Requirements:

Type: Serum
Container/Tube: Red-top tube or gel-barrier tube

  • If a red-top tube is used, transfer the separated serum to a plastic transport tube.

Sample Volume: 2 mL

Minimum Volume: 0.7 mL (Repeat testing is not possible with this specimen volume.)

Storage: Refrigerate specimens after collection.

Stability (collection to time of analysis/testing):

  • Ambient: 6 days
  • Refrigerated: 7 days
  • Frozen: 14 days
  • Freeze/Thaw cycles: Stable (x3)
Rejection Criteria:

  • Citrate plasma specimen
  • Improper labeling


This test is used to evaluate hirsutism and masculinization in women, as well as male testicular function in clinical states in which testosterone-binding proteins may be altered (obesity, cirrhosis, thyroid disorders).


Free: direct analog/radioimmunoassay (RIA); total: liquid chromatography/tandem mass spectrometry (LC/MS-MS)