T4 (Thyroxine), Free

General Information

Lab Name

T4 (Thyroxine), Free

Lab Code

T4FRG

Epic Name

T4 (Thyroxine), Free

Synonyms

Free T4, Free Thyroxine, FT4, T4-Free, thyroid function

Components

Code Name
T4FR T4 (Thyroxine), Free (Beckman)
T4FRRD T4 (Thyroxine), Free (Roche)

Interpretation

Reference Range

See individual components

Ordering & Collection

Specimen Type

Peripheral Blood

Collection

HMC and UW-MT Onsite Locations:

  • Preferred specimen: 4 mL blood in LIME GREEN PST tube.
  • Acceptable specimen: 4 mL blood in ORANGE RST, GOLD SST, RED TOP or GREEN TOP tube.

Offsite Clinic or Other Locations:

  • Preferred specimen: 4 mL blood in GOLD SST tube.
  • Acceptable specimen: 4 mL blood in ORANGE RST or LIME GREEN PST, RED TOP or GREEN TOP tube.

Pediatric specimen if different: 1 Full LIME GREEN MICROTAINER, 1 Full GOLD MICROTAINER

Unacceptable specimens: LAVENDER TOP

Quantity

requested: 1.0 mL
minimum: 0.5 mL

Processing

Refrigerate serum/plasma.

Storage stability:

  • Room temperature: up to 8 hours.
  • Refrigerated: up to 48 hours.
  • Frozen at −20 °C: longer than 48 hours.
  • Important: Thaw sample only once (do not refreeze).

Performance

LIS Dept Code

Chemistry, Automated Panels (CHA)

Performing Location(s)

HMC Chemistry, Automated
206-520-4600

325 9th Ave, Rm # GWH-47, Seattle, WA 98104-2420

UW-NW Main Lab
206-668-1344

UW Medical Center – Northwest
1550 N 115th Street, A200
Seattle, WA 98133

FHCC Fred Hutch Alliance Lab
206-606-1088

825 Eastlake Ave, Seattle, WA 98109

Fax: 206-606-2027
Hours of Operation: 6:00 a.m. - 10:00 p.m.

Includes satellite labs:
• SAIM - Sloan Clinic 1, 6th Floor
• FHH3 - Sloan Clinic 2, 3rd Floor
• FHH4 - Sloan Clinic 2, 4th Floor

UW-MT Chemistry, Automated
206-520-4600

Clinical Lab, Room NW220,
University of Washington Medical Center,
1959 NE Pacific street, Seattle, WA 98195

Frequency

Daily

Available STAT?

No

Billing & Coding

CPT codes

84439

LOINC

3024-7

Interfaced Order Code

UOW6468