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Test Code TTBS Testosterone, Total and Bioavailable, Serum

Test Down Notes

Effective August 22, 2024:  This test is temporarily unavailable due to analytic issues.  The downtime is expected to be >30 days.  Order FFTST as an alternative. See test notification here.


Ordering Guidance


This is the preferred second-level test for suspected increases or decreases in physiologically active testosterone.



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: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Useful For

Recommended second-level test for suspected increases or decreases in physiologically active testosterone:

-Assessment of androgen status in cases with suspected or known sex hormone-binding globulin binding abnormalities

-Assessment of functional circulating testosterone in early pubertal boys and older men

-Assessment of functional circulating testosterone in women with symptoms or signs of hyperandrogenism but normal total testosterone levels

-Monitoring of testosterone therapy or antiandrogen therapy in older men and in females

Profile Information

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

Method Name

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

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

Reporting Name

Testosterone, Total and Bioavail, S

Specimen Type

Serum Red

Specimen Minimum Volume

0.6 mL

Specimen Stability Information

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

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

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, 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 Friday

Report Available

2 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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.

CPT Code Information

84403

84410

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TTBS Testosterone, Total and Bioavail, S 58716-2

 

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