THYROXINE, FREE

Mnemonic

T4F

Synonym

T4 Free - Thyroxine Free - Free T4

Specimen Collection Requirements

Collect

Serum or Plasma, one 5.0 mL gold (SST), 7.0 mL red or 3.0 mL green (sodium or lithium heparin PST) top tube

Handling

Allow serum to clot completely at room temperature (minimum: 30 minutes). Centrifuge and separate serum and plasma from cells ASAP.

Preferred Volume

1.0 mL

Minimum Volume

0.3 mL

Transport

Refrigerated (2-8°C)

Rejection Criteria

Grossly hemolyzed specimens

Stability

AFTER SEPARATION FROM CELLS: Ambient (20-25°C): 5 days; Refrigerated (2-8°C): 7 days; Frozen (at or below -20°C): 30 days.

Testing Information

Performed

Sun - Fri

Method

Chemiluminescent Immunoassay

Referral Lab

Samaritan Health Services Laboratories

Reference Values

Reference Values

ADULT: 0.85-1.71 ng/dL

CPT Codes

84439

Last Updated: Thursday, January 5, 2017 03:42:31 AM