Question 16

A collection tube containing EDTA indicates plasma.

A collection tube that has EDTA as an additive is used to prevent blood from clotting, thereby producing plasma rather than serum upon centrifugation.

A) SST in the collection tube indicates plasma.

SST, or serum separator tubes, contain a gel that separates serum from the clot after centrifugation. However, SST does not directly indicate plasma, as it is specifically designed to yield serum.

B) Sodium fluoride in the collection tube indicates serum.

Sodium fluoride is primarily used as a preservative in blood collection tubes for glucose testing. It does not indicate serum; instead, it is used in conjunction with tubes that yield serum after clotting.

C) Sodium citrate in the collection tube indicates serum.

Sodium citrate is an anticoagulant that prevents blood from clotting, allowing for the collection of plasma rather than serum. Therefore, this option is incorrect in the context of identifying serum.

D) EDTA in the collection tube indicates plasma.

EDTA is an anticoagulant that effectively prevents coagulation, which means that when blood is collected in a tube containing EDTA, it will yield plasma upon centrifugation. This makes this option correct.

Conclusion

The correct identification of a collection tube containing EDTA as indicative of plasma is essential for proper blood testing and analysis. Other options either misrepresent the type of sample produced or incorrectly attribute characteristics of serum to anticoagulants, failing to recognize the role of EDTA in preserving plasma. Thus, option D is the only accurate choice in distinguishing the type of sample based on the anticoagulant present.