Testosterone, Total

Label Mnemonic:	TST
Epic code:	LAB124
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Chemistry
6240 RCP
356-3527

Specimen(s):

Plasma

Collection Medium:

Plasma Separator Tube 4.5 mL

Alternate Collection Media:

Call laboratory for additional acceptable specimen collection containers.

Minimum:

3 mL whole blood in light green top or TWO Microtainer^® devices.

Testing Schedule:

24 hrs/day, 7 days a week, including holidays.

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

Adult Males:
  19-49 years old        249-836 ng/dL
  50 years and older     193-740 ng/dL

Adult Females:
  19-49 years old        8-48 ng/dL
  50 years and older     2-41 ng/dL

Boys
  <1 month              75-400 ng/dL
  1-5 months            14-363 ng/dL
  6-24 months           Less than 37 ng/dL
  2-5 years             Less than 19 ng/dL
  6-9 years             Less than 13 ng/dL
  10-11 years           3-237 ng/dL
  12-13 years           29-432 ng/dL
  14-15 years           40-778 ng/dL
  16-18 years           238-1048 ng/dL

  Tanner stage 1        Less than 15 ng/dL
  Tanner stage 2        3-432 ng/dL
  Tanner stage 3        65-778 ng/dL
  Tanner stage 4        180-763 ng/dL
  Tanner stage 5        188-882 ng/dL

Girls
  Up to 30 days         20-64 ng/dL
  1-5 months            Less than 20 ng/dL
  6-24 months           Less than 9 ng/dL
  2-3 years             Less than 20 ng/dL
  4-5 years             Less than 30 ng/dL
  6-7 years             Less than 13 ng/dL
  8-9 years             1-8 ng/dL
  10-11 years           3-32 ng/dL
  12-13 years           3-50 ng/dL
  14-15 years           6-52 ng/dL
  16-18 years           9-58 ng/dL

  Tanner stage I        Less than 17 ng/dL
  Tanner stage II       Less than 40 ng/dL
  Tanner stage III      5-63 ng/dL
  Tanner stage IV-V     6-58 ng/dL

Interpretive Data:

This assay may be significantly impacted by high-dose biotin (>5 mg dose) taken within previous 12 hours. High concentrations of biotin may lead to falsely increased results. These concentrations may be found in patients taking over-the-counter supplements with biotin content much higher than nutritional requirements for biotin. Specimens should not be collected until at least 12 hours after the last dose.

Comments:

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).

Test Limitations:

The assay is unaffected by icterus (bilirubin is less than 30 
mg/dL), Hemolysis less than 600, lipemia less than 1000 and biotin is 
less than 30 ng/mL (criterion: recovery within plus or minus 10% of 
initial value).

In vitro tests were performed on 20 commonly used pharmaceuticals. A 
strong interaction with Nandrolone was found.  Do not use samples from 
patients under Nandrolone treatment.

The risk of interference from potential immunological interactions 
between test components and rare sera has been minimized by the 
inclusion of suitable additives.

In rare cases, interference due to extremely high titers of antibodies 
to ruthenium can occur.

Testosterone contains additives which minimize these effects.

Extremely high titers of antibodies to streptavidin can occur in 
isolated cases and cause interference.

For diagnostic purposes, the testosterone findings should always be 
assessed in conjunction with the patient's medical history, clinical 
examination and other findings.

Methodology:

Electrochemiluminescence Immunoassay

CPT Code:

84403

See Additional Information:
Biotin Interference with Immunoassays