Question

A blood specimen collected in a heparinized tube is centrifuged. It will separate into:

• A. Plasma, buffy coat, RBC
• B. Serum and Clot
• C. Plasma and Clot
• D. Plasma and Serum

Hint:

Always remember: anticoagulated blood gives plasma after centrifugation, while coagulated blood gives serum.

Answer 1

The Correct Option is A

Step 1: Understanding the role of heparin.
Heparin is an anticoagulant, which means it prevents clotting of blood by inactivating thrombin and other clotting factors. Therefore, when blood is collected in a heparinized tube, it does not form a clot even after standing or centrifugation.
Step 2: Centrifugation process.
When the sample is centrifuged, the heavier components such as red blood cells (RBCs) settle at the bottom of the tube due to gravity. A thin layer called the buffy coat, which consists of leukocytes (WBCs) and platelets, forms in the middle. The lighter component, plasma, remains at the top.
Step 3: Differentiating plasma from serum.
Plasma is the liquid part of unclotted blood and contains fibrinogen and clotting factors. Serum, on the other hand, is obtained only after blood clots. Since heparin prevents clotting, the separated liquid is plasma, not serum.
Step 4: Conclusion.
Thus, centrifugation of heparinized blood separates the components into plasma, buffy coat, and RBCs.
Final Answer:
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