Question 11

EDTA in the collection tube indicates plasma.

EDTA is an anticoagulant that prevents blood from clotting, resulting in a collection tube that contains plasma. Plasma is the liquid component of blood that remains after the cells have been removed, and EDTA effectively preserves this state.

A) SST in the collection tube indicates plasma.

SST, or Serum Separator Tube, actually contains a gel that separates serum from blood cells after centrifugation. It is not indicative of plasma; instead, it is used to collect serum, which forms after blood has clotted.

B) Sodium fluoride in the collection tube indicates serum.

Sodium fluoride is primarily used as a preservative for glucose testing and does not directly indicate whether the tube contains serum. It can be found in tubes designed for serum collection but does not distinguish the presence of plasma.

C) Sodium citrate in the collection tube indicates serum.

Sodium citrate is an anticoagulant that prevents clotting, leading to the collection of plasma rather than serum. Therefore, this option is incorrect as it misidentifies the type of liquid component in the tube.

D) EDTA in the collection tube indicates plasma.

This option is correct as EDTA is an anticoagulant that keeps the blood from clotting, resulting in the collection of plasma. Plasma is the liquid part of the blood that remains when cells are removed, which is what EDTA tubes are designed to collect.

Conclusion

The correct answer is that EDTA in the collection tube indicates plasma, as it prevents clotting and preserves the liquid component of blood. All other options misrepresent the contents or purpose of the tubes, leading to confusion between plasma and serum. Understanding these distinctions is crucial for accurate blood collection and analysis in phlebotomy.