Collect SST/0.8 mL serum, after 30 minutes of clotting promptly centrifuge and send.

Patient Preparation:
Patient should be fasting and have rested for at least 30 minutes prior to collection.

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.