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HelpOrder Code LAB3469 Testosterone, Total and Bioavailable, Serum
Additional Codes
| Mayo Test ID |
|---|
| TTBS |
| EPIC Test ID |
|---|
| LAB3469 |
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.
Reporting Name
Testosterone, Total and Bioavail, SUseful 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
Specimen Type
Serum RedOrdering 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.
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
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Day(s) Performed
Monday through Friday
Method Name
TTST: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
BATS: Differential Precipitation/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
CPT Code Information
84403
84410
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| BATS | Testosterone, Bioavailable, S | No | Yes |
| TTST | Testosterone, Total, S | Yes | Yes |
Method Description
Testosterone, Bioavailable:
The method is based on the differential precipitation of sex hormone-binding globulin (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 (LC-MS/MS). Bioavailable testosterone shows a strong correlation to free testosterone by equilibrium dialysis and may be considered a suitable alternative.(Unpublished Mayo method)
Testosterone, Total:
Deuterated stable isotope (d3-testosterone) is added to a serum sample as internal standard. Protein is precipitated from the mixture. 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. Epitestosterone does not interfere with this LC-MS/MS method for total testosterone.(Unpublished Mayo method)