NHA Phlebotomy Certification Practice Exam

What is the primary purpose of inverting anticoagulant tubes?

1. To encourage coagulation

2. To prevent hemolysis

3. To prevent coagulation

4. To enhance clot formation

The correct answer is: To prevent coagulation

The primary purpose of inverting anticoagulant tubes is to ensure that the anticoagulant within the tube is evenly mixed with the blood sample, which is crucial for preventing clotting. When blood is drawn into an anticoagulant tube, it contains substances that inhibit coagulation. Inverting the tube allows for thorough mixing of the anticoagulant with the blood, effectively preventing the formation of clots that could otherwise compromise the accuracy of test results. When blood coagulates, it leads to the formation of a fibrin clot, which can interfere with laboratory analyses, especially in tests that require liquid plasma or serum. The process of inverting the tube helps maintain the integrity of the sample for accurate testing, confirming that the anticoagulant is functioning properly. In this context, the other provided options do not accurately reflect the purpose of inverting the tubes. Encouraging coagulation or enhancing clot formation would contradict the role of anticoagulants. Preventing hemolysis is a separate consideration and relates more to sample handling and not directly to the action of the anticoagulant. Therefore, the correct understanding rests on the need to mix the anticoagulant thoroughly with the blood sample to prevent coagulation.