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Test ID BLOD0360 Testosterone, Total, Bioavailable, and Free, Serum

Important Note

Early morning testosterone levels in young male individuals are, on average, 50% higher than p.m. levels. Reference values were established using specimens collected in the morning.

 

Effective 3/21/2025:  Due to reagent issues affecting TTFB, results will be delayed past the published turnaround time. Specimens will be stabilized upon arrival and processed in the order they are received. Specimens may take up to 12 days to result and the duration of the delay is expected to last up to 60 days or more. An update will be provided when standard testing resumes.

Useful For

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

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


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

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 a plastic vial


Specimen Minimum Volume

2 mL

Specimen Stability Information

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

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Day(s) Performed

Monday through Saturday

Report Available

3 to 7 days

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)

Reporting Name

Testosterone, Total, Bio, Free, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Secondary ID

83686

CPT Code Information

84402

84403

84410

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

*Forest MG, Cathiard AM, Bertrand JA. Total and unbound testosterone levels in the newborn and in normal and hypogonadal children: use of a sensitive radioimmunoassay for testosterone. 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

*Forest MG, Cathiard AM, Bertrand JA. Total and unbound testosterone levels in the newborn and in normal and hypogonadal children: use of a sensitive radioimmunoassay for testosterone. 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

Test Classification

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

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
Sanford Laboratories - Sioux Falls/Rapid City Additional Information:

SANFORD LABORATORY INTERFACE BUILD INFORMATION

 Result Code     Result Code Description   
 3874  Testosterone Total
 4612  Testosterone Free
 5576  Testosterone Bioavailable