Why is sodium citrate chosen as an anticoagulant for coagulation studies?

Sodium citrate is selected as an anticoagulant for coagulation studies primarily because it prevents clotting factors from functioning, which is essential for accurate testing. By chelating calcium ions in the blood, sodium citrate inhibits the clotting cascade and ensures that the sample remains in a liquid state. This allows healthcare professionals to assess the coagulation status of the patient without the interference of clot formation that would occur if the sample were allowed to clot.

The other options, while related to properties of anticoagulants or blood handling, do not align with the primary role of sodium citrate. For instance, enhancing blood flow or stabilizing blood samples does not accurately describe why sodium citrate is specifically used in coagulation studies. Its core purpose is to ensure that the coagulation factors remain inactive to enable reliable testing results.