Specimen Requirements

Due to interference, patients receiving high doses of biotin (>5 mg/day) should wait at least 8 hours after dose before having blood drawn.

Collection Instructions:

1. Serum and Plasma gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection

Draw blood in a gold-top serum gel tube(s) from a fasting patient. (Green-top [heparin] tube or lavender-top [EDTA] tube or hemolyzed specimen is not acceptable.) Spin down and send 1 mL of serum refrigerated. 

 RMH: Draw blood in a gold-top serum gel tube(s) from a fasting patient. Spin down and send 1 mL of serum refrigerated.

Note:

1. A speckled-top serum gel tube (s) or a plain, red-top tube(s) is also acceptable.

2. Due to a possible interference with folate do not draw from patients who are receiving therapy with methotrexate or leucovorin.

Specimen Stability Information