Days Set Up
Male: daily; Female and Pediatric: varies; 2-3 times per week
Analytic Time

1 - 4 days

MiChart Code
Bioavailable Testosterone, Males; Bioavailable Testosterone, Pediatrics and
Soft Order Code
TTBSM (Male)/TTBSP (Pediatric and Female)

Test Updated:

Synonyms

TTBS
Free Testosterone
Testosterone Binding Index
FT
Bioavailable Testosterone
BIOTEST
Testosterone, Bioavailable and Total
TTBSM
TTBSP

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Test Overview

Test Methodology

Bioavailable Testosterone calculated using the Vermeulen equation.

Test Usage
 
Reference Range

Bioavailable Testosterone: Males Ages 20 – 69, 1.1 – 4.0 ng/mL; Female Ages 20 – 80, 0.01 – 0.19 ng/mL. All other non-specified age ranges do not have established reference ranges. Refer to Total Testosterone (male, female or pediatric) and Sex Hormone Binding Globulin Handbook entries for reference ranges.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Offsite

Refer to Total Testosterone (male, female or pediatric) and Sex Hormone Binding Globulin Handbook entries. There is no additional specimen required for the Bioavailable Testosterone calculation.
Male: Collect blood in an SST tube. Centrifuge, aliquot serum into a plastic vial, and refrigerate.
Female and Pediatric: Collect blood in a red top tube. Centrifuge, aliquot serum into a plastic vial, and refrigerate

Red Top Tube
Normal Volume
1 mL serum
Minimum Volume
0.6 mL serum

Billing Information

CPT Code
TTBSM: 84403, 84270; TTBSP: 84403, 84270
Pro Fee Code
 
LOINC
2986-8 Testosterone; 13967-5 Sex Hormone Binding Globulin

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.