T4 Free, Direct Dialysis
Test Summary
For the differential diagnosis of euthyroid hyperthyroxinemia from hyperthyroidism or for the differential diagnosis of euthyroid hypothyroxinemia from hypothyroidism.
Aliases
- N/A
Specimen Collection
Special Instructions
N/A
Preferred Specimen
1 mL serum
Minimum Volume
0.5 mL
Instructions
Please specify the patient's age on the request form
Patient Preparation
Fasting preferred
Storage
N/A
Transport Temperature
Room temperature
Specimen Stability
- Room temperature: 4 days
- Refrigerated: 14 days
- Frozen: 35 days
Limitations
N/A
Other Acceptable Specimens
N/A
Unacceptable Specimens
Lipemia • Heparin plasma • EDTA plasma
Order Code
T4FREE
EPIC (Premier) Code
LAB3829
Includes
N/A
CPT Code
- 84439
Billing Code
- 700000
CPT Statement
Methodology
Equilibrium Dialysis • Chromatography/Mass Spectrometry
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Physician Attestation of Informed Consent
N/A
Testing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly VA, 20153
14225 Newbrook Drive
Chantilly VA, 20153
Reference Range
| Adult | 0.9-2.2 ng/dL |
| Prematures, 25-30 Weeks | |
| Birth-7 Days | 0.5-3.3 ng/dL |
| Prematures, 31-36 Weeks | |
| Birth-7 Days | 1.3-4.7 ng/dL |
| Cord Blood, >37 Weeks | 1.2-2.2 ng/dL |
| Birth-4 Days | 2.2-5.3 ng/dL |
| 2 Months-2 Years | 1.2-2.5 ng/dL |
| 3 Years-17 Years | 1.0-2.4 ng/dL |
| Pregnancy | |
| First Trimester | 0.9-2.0 ng/dL |
| Second Trimester | 0.8-1.5 ng/dL |
| Third Trimester | 0.8-1.7 ng/dL |
Setup Schedule / Expected Turnaround Time
Monday - Saturday; Report available: 3 - 4 days
Specimen Collection
Special Instructions
N/A
Preferred Specimen
1 mL serum
Minimum Volume
0.5 mL
Instructions
Please specify the patient's age on the request form
Patient Preparation
Fasting preferred
Storage
N/A
Transport Temperature
Room temperature
Specimen Stability
- Room temperature: 4 days
- Refrigerated: 14 days
- Frozen: 35 days
Limitations
N/A
Other Acceptable Specimens
N/A
Unacceptable Specimens
Lipemia • Heparin plasma • EDTA plasma
Result Information
Methodology
Equilibrium Dialysis • Chromatography/Mass Spectrometry
Testing Laboratory
N/A
Reference Range
| Adult | 0.9-2.2 ng/dL |
| Prematures, 25-30 Weeks | |
| Birth-7 Days | 0.5-3.3 ng/dL |
| Prematures, 31-36 Weeks | |
| Birth-7 Days | 1.3-4.7 ng/dL |
| Cord Blood, >37 Weeks | 1.2-2.2 ng/dL |
| Birth-4 Days | 2.2-5.3 ng/dL |
| 2 Months-2 Years | 1.2-2.5 ng/dL |
| 3 Years-17 Years | 1.0-2.4 ng/dL |
| Pregnancy | |
| First Trimester | 0.9-2.0 ng/dL |
| Second Trimester | 0.8-1.5 ng/dL |
| Third Trimester | 0.8-1.7 ng/dL |
Setup Schedule / Expected Turnaround Time
Monday - Saturday; Report available: 3 - 4 days