Which laboratory test category typically requires blood collection in a PST tube?

Which laboratory test category typically requires blood collection in a PST tube?

• A. Complete Blood Count
• B. Coagulation Studies
• C. Chemistry of Plasma
• D. Blood Typing

Answer: (C)

PST tubes are designed to yield plasma for testing. They contain an anticoagulant and a gel separator that keeps plasma separated from the blood cells after centrifugation. Chemistry of plasma relies on measuring substances in the plasma, so these tubes are routinely used for that category. Other tests—like complete blood count, which requires intact cells; coagulation studies, which use citrate to prevent clotting, and different tube types; and blood typing, which often uses serum or specific plasma/serum preparations—do not rely on the PST’s plasma-focused setup.

PST tubes are designed to yield plasma for testing. They contain an anticoagulant and a gel separator that keeps plasma separated from the blood cells after centrifugation. Chemistry of plasma relies on measuring substances in the plasma, so these tubes are routinely used for that category. Other tests—like complete blood count, which requires intact cells; coagulation studies, which use citrate to prevent clotting, and different tube types; and blood typing, which often uses serum or specific plasma/serum preparations—do not rely on the PST’s plasma-focused setup.