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Order Code LABFFTST Testosterone, Free and Weakly Bound, With Total Testosterone, LC/MS-MS

Additional Codes

Mayo Test Code: FFTST

EPIC Test Code: LABFFTST


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

Performing Laboratory

LabCorp Burlington

CPT Code Information

84410