Which anticoagulant is commonly associated with PST tubes?

Which anticoagulant is commonly associated with PST tubes?

• A. EDTA
• B. Citrate
• C. Oxalate
• D. Heparin

Answer: (D)

PST tubes are designed to yield plasma by separating it from cells after centrifugation, so they need an anticoagulant that prevents clotting without significantly interfering with most chemistry tests. The anticoagulant commonly used in PST tubes is heparin—typically lithium heparin—because it stops clotting quickly and preserves plasma for a wide range of analyses. This makes PST tubes suitable for many chemistry panels where you want plasma to remain fluid and representative of the patient’s circulating constituents. Other anticoagulants are associated with different tube types and tests. EDTA is used mainly for preserving cellular components in complete blood counts and can alter some plasma chemistry measurements. Citrate is chosen for coagulation studies due to its calcium-chelating effect, which is not desirable for routine plasma chemistry. Oxalate is often paired with fluoride for glucose testing, again with different testing goals. Thus, heparin is the best match for PST tubes because it supports plasma-based chemistry work without the limitations these other additives impose.

PST tubes are designed to yield plasma by separating it from cells after centrifugation, so they need an anticoagulant that prevents clotting without significantly interfering with most chemistry tests. The anticoagulant commonly used in PST tubes is heparin—typically lithium heparin—because it stops clotting quickly and preserves plasma for a wide range of analyses. This makes PST tubes suitable for many chemistry panels where you want plasma to remain fluid and representative of the patient’s circulating constituents.

Other anticoagulants are associated with different tube types and tests. EDTA is used mainly for preserving cellular components in complete blood counts and can alter some plasma chemistry measurements. Citrate is chosen for coagulation studies due to its calcium-chelating effect, which is not desirable for routine plasma chemistry. Oxalate is often paired with fluoride for glucose testing, again with different testing goals. Thus, heparin is the best match for PST tubes because it supports plasma-based chemistry work without the limitations these other additives impose.