If you need serum for a test, you should use a syringe without an anticoagulant.

• A. True
• B. False
• C. Use only if testing is urgent
• D. Anticoagulant is optional

Answer: (A)

When a test requires serum, you want the liquid that remains after the blood has clotting. Anticoagulants prevent clotting, so using a syringe with an anticoagulant stops the clotting process and produces plasma instead of serum. To obtain serum, collect blood in a syringe or tube without anticoagulant, allow it to clot, then separate the serum by centrifugation. If an anticoagulant is present, you won’t get serum, which could affect tests that specifically require serum. So the statement is correct.