| Laboratory: | Clinical Biochemistry (SBH ONLY - AUTO) | ||||||||||||||||||||
| Test Name: |
TESTOSTERONE TOTAL, BIOAVAILABLE and FREE (CALCULATED) - (S)
Test Code:
FTST
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| Clinical Information: |
Description: Provides a calculated value for bioavailable and free testosterone concentration using measured total testosterone (immunoassay), sex hormone binding globulin (SHBG) and albumin levels.
Test Indications: It is useful in evaluation of hypogonadism in males with low total testosterone levels or in individuals with altered protein binding. It may also be used to monitor testosterone hormone therapy. It is not recommended for children or females. Patient preparation instructions: Fasting is preferred, but not required. |
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| Collection Devices: |
Acceptable specimen include serum with or without gel
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| Specimen Required: |
Plasma: 2.0 mL
Collection Information: Collect morning specimen (6 AM-10 AM). Special Processing: Samples must be transferred to an aliquot tube and stored frozen if analysis will not be complete within 48 hours. Specimen Stability: Ambient: 48 h Refrigerated: 1 week Frozen: 2 months |
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| Referral: |
Plasma: 2.0 mL
Shipping & Storage: Store and ship frozen. Avoid repeated freeze-thaw cycles.
Testing Laboratory (MB): Ship to: St. Boniface Hospital - Biochemistry Laboratory Rm. L3041 (SHBG testing is only performed at St. Boniface hospital) Measure SHBG, albumin and total testosterone to calculate free and bioavailable testosterone. |
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| Requisition: | |||||||||||||||||||||
| Reference Values: |
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| Availability: |
Routine
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| See Also: | |||||||||||||||||||||
| More Information: |
Free and bioavailable testosterone are calculated according to Vermeulen equation.
Alex Vermeulen, Lieve Verdonck, Jean M. Kaufman, A Critical Evaluation of Simple Methods for the Estimation of Free Testosterone in Serum, J Clin Endocrinol Metab 1999; 84:3666–3672. |