Specimen Requirements

Specimen Type: Plasm or serum 

Container/Tube:

Serum: Yellow top or Red top

Plasma: Green top 

Specimen Volume: 1 mL

The VITROS TSH assay tolerates up to 2–5 ng/mL of Biotin/Vitamin B7. Patients taking high-dose supplements may exceed this threshold, resulting in falsely low TSH values.  It's recommended that Biotin supplementation be discontinued 48 hours prior to blood draw