Pre-Testing Requirements:
Patients who are undergoing biotin therapy and/or ingesting biotin supplements with levels of >100ng/mL will show a falsely high TT3 result in the Beckman TT3 assay.
Aliquot Instructions
Sample Type
Serum
Plasma
Minimum Volume (ml)
1.0
Transport to Lab
Frozen
If overnight - Frozen
Additional Referral/Aliquot Information
Minimum 1.0 ml serum. Ideally 1.5 ml. This volume allows all total thyroid function tests to be performed. Fridge 4C.
Reference Intervals
1.3 – 2.7 nmol/L (Manufacturers data).
Test Method
Beckman-Coulter Access Analyser - CMIA
Non-Funded Test Cost
$28.96 (Exclusive of GST)
Billing Code
8865
EDTA not acceptable.
Adjunct to primary thryoid function screen.
Automated method with different reference range introduced 22 August 2014
