Specimen Required

Patient Preparation:

1. Fasting: 12 hours, required

2. For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).

3. For 1 week before specimen collection, if medically feasible, patient should not take proton pump inhibitors (omeprazole, lansoprazole, dexlansoprazole, esomeprazole, pantoprazole, and rabeprazole).

4. For at least 2 weeks before specimen collection, patient should not take or receive drugs that interfere with gastrointestinal motility (eg, opioids).

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. If multiple specimens are collected, submit each vial under a separate order.

2. Label specimens with corresponding collection time.

3. Centrifuge at within 2 hours of collection. Refrigerated centrifugation is preferred but not required. Immediately aliquot serum into plastic vial.