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Test Code FFTST Testosterone, Free and Weakly Bound, With Total Testosterone, LC/MS-MS


Specimen Required


Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/tube: Plastic vial

Specimen Volume: 2 mL

Collection Instructions:

1. Draw blood in a plain red-top tube(s).

2. Within one hour of collection, centrifuge and aliquot 2 mL serum into a plastic vial.

3. Ship refrigerated.


Method Name

Ammonium sulfate precipitation; liquid chromatography/tandem mass spectrometry (LC/MS-MS)

Reporting Name

Testosterone,F/WklyBd+T LC/MS

Specimen Type

Serum

Specimen Minimum Volume

1.4 mL (does not allow for repeat testing)

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
  Ambient  7 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

Males:

Age:

Range (ng/dL):

Premature Infants (26 to 28 weeks) Day 4

59.0-125.0

Premature (31-35 weeks) Day 4

37.0-198.0

Newborns

75.0-400.0

Prepubertal (1 to 10 years)

<2.5-10.0

1 to 7 Months

Levels decrease rapidly the first week to 20.0-50.0 ng/dL, then increase to 60.0-400.0 ng/dL (mean=190.0) between 20-60 days. Levels then decline to prepubertal range of <2.5-10.0 by seven months.

 

Females:

Age:

Range (ng/dL):

Premature Infants (26 to 28 weeks) Day 4

5.0-16.0

Premature (31-35 weeks) Day 4

5.0-22.0

Newborns

20.0-64.0

Prepubertal (1 to 9 years)

<2.5-10.0

 

1 to 7 Months

Levels decrease during the first month to <10.0 ng/dL and remain there until puberty.

 

Puberty:

Tanner Stage (Males)

Age (Years)

Range (ng/dL)

Mean (ng/dL)

1

<9.8

<2.5-10.0

4.9

2

9.8-14.5

18.0-150.0

42.0

3

10.7-15.4

100.0-320.0

190.0

4

11.8-16.2

200.0-620.0

372.0

5

12.8-17.3

350.0-970.0

546.0

 

Tanner Stage (Females)

Age (Years)

Range (ng/dL)

Mean (ng/dL)

1

<9.2

<2.5-10.0

4.9

2

9.2-13.7

7.0-28.0

18.0

3

10.0-14.4

15.0-35.0

25.0

4

10.7-15.6

13.0-32.0

22.0

5

11.8-18.6

20.0-38.0

28.0

 

Adults:

≥18 Years

Range (ng/dL)

Males

350.0-1030.0

Females

Premenopausal

10.0-55.0

Postmenopausal

7.0-40.0

 

Testosterone % Free+Weakly Bound:

Female: 3.0-18.0%

Male: 9.0-46.0%

 

Testosterone, F+W Bound:

Female: 0.0-9.5 ng/dL

Male: 40.0-250.0 ng/dL

Day(s) Performed

Daily

Report Available

6 to 10 days

Performing Laboratory

LabCorp Burlington

Test Classification

This test was developed, and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

CPT Code Information

84410