Specimen Requirements
Title
Hemoglobin
Specimen Requirement
Lavender Top
Methodology
Stability
Reference Range
Turnaround
Clinical Use
Test Code
HGB
Thyroid Testing Update: Effective 02/01/2026, T3 Uptake will be discontinued and replaced with Free T4 testing. Free T4 more directly reflects active thyroxine levels and supports clearer clinical interpretation than older, indirect binding assessments. (Click here for more information)