T4 (Thyroxine), Free (Roche)

General Information

Lab Name

T4 (Thyroxine), Free (Roche)

Lab Code

T4FRRD

Epic Name

(not orderable in Epic)

Synonyms

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

Interpretation

Method

Competitive immunoassay on Roche Cobas e801.

Reference Range

Units: ng/dL
Female Male Unknown
AgeRange AgeRange AgeRange
0-0.9-1.7 0-0.9-1.7 0-0.9-1.7

Effective date: 04/03/2026

Ordering & Collection

Specimen Type

Peripheral Blood

Collection

  • 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)

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

Frequency

Available STAT?

Billing & Coding

CPT codes

LOINC

3024-7

Interfaced Result Code

UOW6469