Please call Clinical Labs of Hawaii at 808.677.7998 (Option 1) with questions about this test.
Synonyms
FT4
Free Thyroxine
Patient Preparation
For 8 hours before this test, if feasible, the patient should not take multivitamins or dietary hair and nail supplements containing high doses of biotin or vitamin B7 (i.e. 5-10 mg/day). In mega doses (>10-150 mg/day), the supplement should be withheld for at least 2-3 days.
Specimen Preparation
1.0 mL (0.5 mL minimum) Serum SST or Red top or Plasma Lithium Heparin (Green top)
Stability (from collection to initiation)
Room temperature: 5 days Refrigerated: 7 days Frozen: 1 month
Unacceptable Conditions
Heat-inactivated samples or samples stabilized with azide.
Storage/Transport Temperature
Refrigerated
Reported
Performed: Sun-Mon Reported: 1-2 days
Methodology
Electrochemiluminescence Immunoassay (ECLIA)
Test Site
Clinical Labs of Hawaii
Reference Interval
0.6-1.7 ng/dL
CPT Codes
84439
LOINC
3024-7
Patient Preparation
For 8 hours before this test, if feasible, the patient should not take multivitamins or dietary hair and nail supplements containing high doses of biotin or vitamin B7 (i.e. 5-10 mg/day). In mega doses (>10-150 mg/day), the supplement should be withheld for at least 2-3 days.
Specimen Preparation
1.0 mL (0.5 mL minimum) Serum SST or Red top or Plasma Lithium Heparin (Green top)
Storage/Transport Temperature
Refrigerated
Stability (from collection to initiation)
Room temperature: 5 days Refrigerated: 7 days Frozen: 1 month
Unacceptable Conditions
Heat-inactivated samples or samples stabilized with azide.
LOINC
3024-7
Synonyms
FT4
Free Thyroxine
CPT Codes
84439
Test Code
FT4
Ordering Code
0268
Reported
Performed: Sun-Mon Reported: 1-2 days
Methodology
Electrochemiluminescence Immunoassay (ECLIA)
Reference Interval
0.6-1.7 ng/dL
Test Site
Clinical Labs of Hawaii
Summary
Test Code
FT4
Ordering Code
0268
Questions?
Please call Clinical Labs of Hawaii at 808.677.7998 (Option 1) with questions about this test.
Synonyms
FT4
Free Thyroxine
Patient Preparation
For 8 hours before this test, if feasible, the patient should not take multivitamins or dietary hair and nail supplements containing high doses of biotin or vitamin B7 (i.e. 5-10 mg/day). In mega doses (>10-150 mg/day), the supplement should be withheld for at least 2-3 days.
Specimen Preparation
1.0 mL (0.5 mL minimum) Serum SST or Red top or Plasma Lithium Heparin (Green top)
Stability (from collection to initiation)
Room temperature: 5 days Refrigerated: 7 days Frozen: 1 month
Unacceptable Conditions
Heat-inactivated samples or samples stabilized with azide.
Storage/Transport Temperature
Refrigerated
Reported
Performed: Sun-Mon Reported: 1-2 days
Methodology
Electrochemiluminescence Immunoassay (ECLIA)
Test Site
Clinical Labs of Hawaii
Reference Interval
0.6-1.7 ng/dL
CPT Codes
84439
LOINC
3024-7
Collection
Patient Preparation
For 8 hours before this test, if feasible, the patient should not take multivitamins or dietary hair and nail supplements containing high doses of biotin or vitamin B7 (i.e. 5-10 mg/day). In mega doses (>10-150 mg/day), the supplement should be withheld for at least 2-3 days.
Specimen Preparation
1.0 mL (0.5 mL minimum) Serum SST or Red top or Plasma Lithium Heparin (Green top)
Storage/Transport Temperature
Refrigerated
Stability (from collection to initiation)
Room temperature: 5 days Refrigerated: 7 days Frozen: 1 month
Unacceptable Conditions
Heat-inactivated samples or samples stabilized with azide.
