Adult patient (for male only):
Clotted blood tube
(Serum gel separator clot activator tube)
Minimum blood volume: 5 mL
Paediatric patient:
Paediatric clotted blood tube
Number of vials: 2
Minimum blood volume: 1.6 mL
Authorisation code required
No
24 Hr available service
No
Method
Immunoassay
Reference interval
Male:
|
0 - 30 days: |
2.6 - 13.9 nmol/L |
| 1 - 5 months: | < 6.1 nmol/L |
| 6 - 12 months: | < 0.2 nmol/L |
| 1 - 5 years: | < 0.9 nmol/L |
| 6 - 9 years: | < 1.0 nmol/L |
| 10 - 19 years: | |
| Tanner stage | I < 0.8 nmol/L |
| II < 2.4 nmol/L | |
| III 0.5 - 9.7 nmol/L | |
| IV 3.6 - 18.9 nmol/L | |
| V 9.2 - 27.8 nmol/L | |
| > 20 years: | 9 - 34.7 nmol/L |
| TETOREI: New reference interval is effective from 18/03/2010 | |
Source:
Roberts WL et al. Reference Information for the Clinical Laboratory. In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics 4th ed: Elsevier Saunders Missouri, U.S.A.
Clinical indication
Investigation of testicular failure or precocious puberty in males
Result interpretation
Levels are increased in males with precocious puberty.
Decreased levels are found in males with testicular failure, either primary or secondary to hypopituitarism.
In plasma, testosterone is bound to sex hormone-binding globulin (SHBG), so abnormal levels of SHBG may cause a discrepancy between free and total testosterone.
Measurement of uncertainty
Frequency of measurement
Daily