Testosterone, Free and Total, Adult

Label Mnemonic:	FTSTM
Epic code:	LAB4140
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Chemistry
6240 RCP
356-3527

Specimen(s):

Plasma

Specimen Instructions:

Specimen should ideally be collected between 6:00 - 10:00 a.m.

Not recommended for children 8 years and younger (especially girls) due to lower concentrations of total testosterone that may be below assay limit of detection. For females or children, see the link below for "Testosterone, Free and Total, Females or Children".

Collection Medium:

Plasma Separator Tube 4.5 mL

Minimum:

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

Rejection Criteria:

EDTA plasma

Testing Schedule:

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

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

Testosterone, total
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           3-327 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

Sex hormone binding globulin
  Males 10-80 nmol/L
  Females, non-pregnant 20-130 nmol/L
Reference ranges not well established during pregnancy.

Free testosterone 
Males
  0-9 years             Less than 1 pg/mL
  10-11 years           Less than 4 pg/mL
  12-13 years           Less than 68 pg/mL
  14-15 years           2-95 pg/mL 
  16-17 years           26-119 pg/mL 
  18 years and older    32-168 pg/mL 

  Tanner stage I        Less than 3 pg/mL
  Tanner stage II       Less than 15 pg/mL
  Tanner stage III      Less than 68 pg/mL
  Tanner stage IV       24-117 pg/mL
  Tanner stage V        28-165 pg/mL 

Females
  0-9 years             Less than 1 pg/mL
  10-11 years           Less than 3 pg/mL
  12-13 years           Less than 5 pg/mL
  14-15 years           Less than 6 pg/mL
  16-17 years           Less than 7 pg/mL
  18-30 years           1-5 pg/mL
  31-40 years           1-6 pg/mL
  41-50 years           1-4 pg/mL
  51 years and older    Less than 3 pg/mL

  Tanner stage I        1-12 pg/mL
  Tanner stage II       4-28 pg/mL
  Tanner stage III      7-44 pg/mL
  Tanner stage IV-V     8-43 pg/mL

% free testosterone 1.1-2.5%

Interpretive Data:

The concentration of free testosterone is derived from a mathematical expression based on the constant for the binding of testosterone to sex hormone binding globulin.

Methodology:

Electrochemiluminescence Immunoassay

CPT Code:

84403 Testosterone, 84270 Sex Hormone Binding Globulin