Specimen Requirements

Specimen must be drawn prior to any blood transfusions.

Container/Tube:

Preferred: Gold top serum gel

Acceptable: Plain red-top tube

Minimum Specimen Volume: 0.5 mL

Stability: Stable for 2 hours at 15‑25 °C, 48 hours at 2‑8 °C, 56 days at ‑20 °C (± 5 °C). Freeze only once. Stability of serum obtained with separating tubes: 24 hours at 2-8 °C. 

Collection Instructions: Fasting specimen is preferred. Protect specimen from light to prevent deterioration. If there is a delay in transport of >72 hours or if mailing time exceeds 72 hours, send specimen frozen in plastic vial. 

Note: 1. This assay is affected by biotin interference.