| 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 # |
T4 (Thyroxine), Free, Plasma or Serum
Test CodeFree T4/FT4 - NOCO
CPT Codes
84439
Preferred Specimen
1 mL plasma from Green top (Lithium Heparin)
Minimum Volume
0.5 mL
Note: For neonate requirements see Neonate Minimum Blood Volumes
Note: For neonate requirements see Neonate Minimum Blood Volumes
Other Acceptable Specimens
1.0 mL serum from SST or Red Top
Specimen Stability
| Specimen Type | Temperature | Time |
| Serum SST | Refrigerated | 7 days |
| Red Top – Separated* | Refrigerated | 7 days |
| Plasma Li Hep | Refrigerated | 7 days |
*Centrifuge and aliquot into a plastic vial.
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis, Collection after IV contrast material
Methodology
Chemiluminescence
Setup Schedule
Monday through Sunday; Continuously
Report Available
Same day
Reference Range
0 - 31 days: 0.8 - 2.2 ng/mL
31 days - 7 months: 0.8 - 1.8 ng/mL
7 months - 1 year: 0.8 1.6 ng/mL
1 - 7 years: 0.9 - 1.4 ng/mL
7 - 12 years: 0.9 - 1.6 ng/mL
12-18 years: 0.90-1.50 ng/mL
18-150 years: 0.80-1.70 ng/mL
31 days - 7 months: 0.8 - 1.8 ng/mL
7 months - 1 year: 0.8 1.6 ng/mL
1 - 7 years: 0.9 - 1.4 ng/mL
7 - 12 years: 0.9 - 1.6 ng/mL
12-18 years: 0.90-1.50 ng/mL
18-150 years: 0.80-1.70 ng/mL
Performing Laboratory
Banner Fort Collins Medical Center Laboratory
Mckee Medical Center Laboratory
North Colorado Medical Center Laboratory
Summit View Laboratory
