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Test Code TESTF Testosterone, Total, Bioavailable, and Free, Serum

Reporting Name

Testosterone, Total, Bio, Free, S

Useful For

Second- or third-order test for evaluating testosterone status (eg, when abnormalities of sex hormone-binding globulin are present)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum Red


Ordering Guidance


The preferred test for diagnosis of mild abnormalities of testosterone homeostasis, particularly if abnormalities in sex hormone-binding globulin function or levels are present, is TTBS / Testosterone, Total and Bioavailable, Serum.



Necessary Information


Patient's age and sex are required.



Specimen Required


Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 3.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 14 days
  Frozen  60 days

Reference Values

TESTOSTERONE, TOTAL

Males

0-5 months: 75-400 ng/dL

6 months-9 years: <7-20 ng/dL

10-11 years: <7-130 ng/dL

12-13 years: <7-800 ng/dL

14 years: <7-1,200 ng/dL

15-16 years: 100-1,200 ng/dL

17-18 years: 300-1,200 ng/dL

≥19 years: 240-950 ng/Dl

Tanner Stages*

I (prepubertal): <7-20

II: 8-66

III: 26-800

IV: 85-1,200

V (young adult): 300-950

 

Females

0-5 months: 20-80 ng/dL

6 months-9 years: <7-20 ng/dL

10-11 years: <7-44 ng/dL

12-16 years: <7-75 ng/dL

17-18 years: 20-75 ng/dL

≥19 years: 8-60 ng/dL

Tanner Stages*

I (prepubertal): <7-20

II: <7-47

III: 17-75

IV: 20-75

V (young adult): 12-60

*Puberty onset (transition from Tanner stage I to Tanner stage II) occurs for boys at a median age of 11.5 (±2) years and for girls at a median age of 10.5 (±2) years. There is evidence that it may occur up to 1 year earlier in obese girls and in African American girls. For boys, there is no definite proven relationship between puberty onset and body weight or ethnic origin. Progression through Tanner stages is variable. Tanner stage V (young adult) should be reached by age 18.

 

TESTOSTERONE, FREE

Males (adult):

20-<25 years: 5.25-20.7 ng/dL

25-<30 years: 5.05-19.8 ng/dL

30-<35 years: 4.85-19.0 ng/dL

35-<40 years: 4.65-18.1 ng/dL

40-<45 years: 4.46-17.1 ng/dL

45-<50 years: 4.26-16.4 ng/dL

50-<55 years: 4.06-15.6 ng/dL

55-<60 years: 3.87-14.7 ng/dL

60-<65 years: 3.67-13.9 ng/dL

65-<70 years: 3.47-13.0 ng/dL

70-<75 years: 3.28-12.2 ng/dL

75-<80 years: 3.08-11.3 ng/dL

80-<85 years: 2.88-10.5 ng/dL

85-<90 years: 2.69-9.61 ng/dL

90-<95 years: 2.49-8.76 ng/dL

95-100+ years: 2.29-7.91 ng/dL

 

Males (children):

<1 year: Term infants

1-15 days: 0.20-3.10 ng/dL*

16 days-1 year: Values decrease gradually from newborn (0.20-3.10 ng/dL) to prepubertal levels

*J Clin Endocrinol Metab 1973;36(6):1132-1142

 

1-8 years: <0.13 ng/dL

9 years: <0.13-0.45 ng/dL

10 years: <0.13-1.26 ng/dL

11 years: <0.13-5.52 ng/dL

12 years: <0.13-9.28 ng/dL

13 years: <0.13-12.6 ng/dL

14 years: 0.48-15.3 ng/dL

15 years: 1.62-17.7 ng/dL

16 years: 2.93-19.5 ng/dL

17 years: 4.28-20.9 ng/dL

18 years: 5.40-21.8 ng/dL

19 years: 5.36-21.2 ng/dL

 

Females (adult):

20-<25 years: <0.13-1.08 ng/dL

25-<30 years: <0.13-1.06 ng/dL

30-<35 years: <0.13-1.03 ng/dL

35-<40 years: <0.13-1.00 ng/dL

40-<45 years: <0.13-0.98 ng/dL

45-<50 years: <0.13-0.95 ng/dL

50-<55 years: <0.13-0.92 ng/dL

55-<60 years: <0.13-0.90 ng/dL

60-<65 years: <0.13-0.87 ng/dL

65-<70 years: <0.13-0.84 ng/dL

70-<75 years: <0.13-0.82 ng/dL

75-<80 years: <0.13-0.79 ng/dL

80-<85 years: <0.13-0.76 ng/dL

85-<90 years: <0.13-0.73 ng/dL

90-<95 years: <0.13-0.71 ng/dL

95-100+ years: <0.13-0.68 ng/dL

 

Females (children):

<1 year: Term infants

1-15 days: <0.13-0.25 ng/dL*

16 days-1 year: Values decrease gradually from newborn (<0.13-0.25 ng/dL) to prepubertal levels

*J Clin Endocrinol Metab 1973;36(6):1132-1142

 

1-4 years: <0.13 ng/dL

5 years: <0.13 ng/dL

6 years: <0.14 ng/dL

7 years: <0.13-0.23 ng/dL

8 years: <0.13-0.34 ng/dL

9 years: <0.13-0.46 ng/dL

10 years: <0.13-0.59 ng/dL

11 years: <0.13-0.72 ng/dL

12 years: <0.13-0.84 ng/dL

13 years: <0.13-0.96 ng/dL

14 years: <0.13-1.06 ng/dL

15-18 years: <0.13-1.09 ng/dL

19 years: <0.13-1.08 ng/dL

 

TESTOSTERONE, BIOAVAILABLE

Males

≤19 years: Not established

20-29 years: 83-257 ng/dL

30-39 years: 72-235 ng/dL

40-49 years: 61-213 ng/dL

50-59 years: 50-190 ng/dL

60-69 years: 40-168 ng/dL

≥70 years: Not established

 

Females (non-oophorectomized)

≤19 years: Not established

20-50 years (on oral estrogen): 0.80-4.0 ng/dL

20-50 years (not on oral estrogen): 0.80-10 ng/dL

>50 Years: Not established

Day(s) Performed

Monday through Saturday

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

84402

84403

84410

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TTFB Testosterone, Total, Bio, Free, S 58716-2

 

Result ID Test Result Name Result LOINC Value
82978 Testosterone, Bioavailable, S 2990-0
3631 Testosterone Free 2991-8
8533 Testosterone, Total, S 2986-8

Clinical Reference

1. Manni A, Pardridge WM, Cefalu W, et al: Bioavailability of albumin-bound testosterone. J Clin Endocrinol Metab. 1985 Oct;61(4):705- 710. doi: 10.1210/jcem-61-4-705.

2. New MI, Josso N: Disorders of gonadal differentiation and congenital adrenal hyperplasia. Endocrinol Metab Clin North Am. 1988;17(2):339-366

3. Dumesic DA: Hyperandrogenic anovulation: a new view of polycystic ovary syndrome. Postgrad Obstet Gynecol. 1995 June;15(13)

4. Morley JE, Perry HM 3rd: Androgen deficiency in aging men: role of testosterone replacement therapy. J Lab Clin Med. 2000 May;135:370-378. doi: 10.1067/mlc.2000.106455

5. Goldman AL, Bhasin S, Wu FCW, et al: A reappraisal of testosterone's binding in circulation: physiological and clinical implications. Endocr Rev. 2017;38(4):302-324. doi: 10.1210/er.2017-00025

Method Description

Total Testosterone:

Deuterated stable isotope (d3-testosterone) is added to a 0.2-mL serum sample as an internal standard. Protein is precipitated from the mixture by the addition of acetonitrile. The testosterone and internal standard are extracted from the resulting supernatant by an online extraction utilizing high-throughput liquid chromatography. This is followed by conventional liquid chromatography and analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source.(Wang C, Catlin DH, Demers LM, et al: Measurement of total testosterone in adult men: comparison of current laboratory methods versus liquid chromatography-tandem mass spectrometry. J Clin Endocrinol Metab. 2004 Feb;89(2):534-543; Taieb J, Mathian B, Millot F, et al: Testosterone measured by 10 immunoassays and by isotope-dilution gas chromatography-mass spectrometry in sera from 116 men, women, and children. Clin Chem. 2003 Aug;49:1381-1395)

 

Free Testosterone:

This method utilizes equilibrium dialysis to analyze and determine the host serum's binding capacity for testosterone. Patient sample is placed inside a dialysis well which is immersed in dialysis buffer. The sample is dialyzed. During buffered dialysis, any testosterone which is unbound to sex hormone binding globulin (SHBG) or albumin is free to pass through the semi-permeable dialysis membrane while those testosterone molecules bound to the binding proteins will be held inside the membrane. After dialysis, the buffered dialysate is analyzed for free testosterone by liquid chromatography-tandem mass spectrometry.(Bhasin S, Ozimek N: Optimizing diagnostic accuracy and treatment decisions in men with testosterone deficiency. Endocr Pract. 2021 Dec;27(12):1252-1259. doi: 10.1016/j.eprac.2021.08.002)

 

Bioavailable Testosterone:

The method is based on the differential precipitation of SHBG. SHBG bound testosterone is precipitated in patient sample, leaving the bioavailable testosterone in the supernatant. After addition of (13)C-labeled testosterone internal standard (IS), the bioavailable testosterone and IS are extracted from the supernatant. The bioavailable testosterone and IS are then derivatized and analyzed by liquid chromatography tandem mass spectrometry. Bioavailable testosterone shows a strong correlation to free testosterone by equilibrium dialysis and may be considered a suitable alternative.(Unpublished Mayo Method)

Report Available

3 to 5 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Method Name

FRTST: Equilibrium Dialysis / Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

TTST: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

BATS: Differential Precipitation/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Profile Information

Test ID Reporting Name Available Separately Always Performed
TTST Testosterone, Total, S Yes Yes
FRTST Testosterone, Free, S No Yes
BATS Testosterone, Bioavailable, S No Yes

Secondary ID

83686