Specimen Required

Patient Preparation:

1. Fasting (8 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.