| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
TESTOSTERONE, TOTAL
Test CodeLAB124
Quest Code
873
CPT Codes
84403
Preferred Specimen
1 mL serum
Patient Preparation
Due to changes in testosterone levels throughout the day, two morning (8:00-10:00 a.m.) specimens obtained on different days are recommended by The Endocrine Society for screening.
Minimum Volume
0.5 mL
Instructions
Dietary supplements containing biotin may interfere in assays and may skew results to be either falsely high or falsely low. For patients receiving the recommended daily doses of biotin, draw samples at least 8 hours following the last biotin supplementation. For patients on mega-doses of biotin supplements, draw samples at least 72 hours following the last biotin supplementation.
Note: This assay should be performed on adult (≥18 years) males.
Note: This assay should be performed on adult (≥18 years) males.
Transport Container
Serum Separator Tube (SST)
All test requests for Testosterone on female and pediatric (<18 years) patients must use plain RED TOP tube.
All test requests for Testosterone on female and pediatric (<18 years) patients must use plain RED TOP tube.
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 5 days
Refrigerated: 7 days
Frozen: 21 days
Refrigerated: 7 days
Frozen: 21 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Grossly icteric
Methodology
Immunoassay (IA)
Setup Schedule
Tues-sat
Report Available
1-4 days
Limitations
Immunoassay does not provide sufficient sensitivity in detecting low concentrations among non-adults and women.
Reference Range
| Adult Male | 250-827 ng/dL |
Current guidelines from many professional societies, including the Endocrine Society and the Menopause Society recommend Liquid Chromatography - Mass Spectrometry (LCMS) testing (TC 15983) for women, children (< 18 years), and men with hypogonadism. LCMS is more accurate and less prone to interfering substances (such as biotin) when low levels of testosterone are suspected. Immunoassays are useful for routine screening or tracking of testosterone levels in adult patients where diagnoses are not being made and testosterone levels are expected to be stable. No reference intervals have been established for female patients or any patient under the age of 18.
Clinical Significance
Testosterone circulates almost entirely bound to transport proteins: Normally less than 1-2% is free. The principal transport protein for testosterone is known as sex hormone binding globulin (SHBG) or testosterone-estradiol binding globulin (TeBG). Testosterone measurements are used to assess erectile dysfunction, infertility, gynecomastia, and osteoporosis and to assess hormone replacement therapy.
Performing Laboratory
| Quest Diagnostics-Lenexa |
| 10101 Renner Blvd |
| Lenexa , KS 66219-9752 |
Last Updated: October 7, 2021
