Free T4 (Blood)

Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Chemical Pathology

Delphic Registration Code (Alpha Code)

FT4

Test Code (Numeric Code)

3024

Laboratory Handling

Sample Stability

5 days at 20-25°C, 7 days at 2-8°C, 30 days at -20°C

Synonyms

FT4, T4, Thyroxine free

Turnaround Time

3 hours

Specimen Type

  • Plasma
  • Serum

Specimen Requirements

Tube/Container Type:

Preferred
  • Lithium Heparin PST- Gel (Light Green Cap)
Acceptable
  • EDTA (Lavender Cap)
  • Lithium Heparin - Non-gel (Green Cap)
  • Plain (Red Top)
  • SST II (Gold Cap)
Preferred Sample Volume (ml)

5

Minimum Sample Volume (ml)

3.5

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • Lithium Heparin PST- Gel (Light Green Cap)
Acceptable
  • EDTA (Lavender Cap)
  • Lithium Heparin - Non-gel (Green Cap)
  • Plain (Red Top)
Preferred Sample Volume (ml)

0.5

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

0.5 mL Paediatric Microtainer PST Blood (Preferred)
0.5 mL Paediatric Microtainer Heparin Blood
0.5 mL Paediatric Microtainer Plain Blood
0.5 mL Paediatric Microtainer EDTA Blood

Last updated: 05/08/2026