How does EDTA keep blood from clotting?

How does EDTA keep blood from clotting?

• A. EDTA binds calcium ions, blocking clotting Cascade and preventing clotting
• B. EDTA chelates magnesium
• C. EDTA neutralizes thrombin
• D. EDTA enhances platelet aggregation

Answer: (A)

Calcium ions are essential cofactors for the steps that drive blood coagulation. EDTA keeps blood from clotting by binding calcium ions so they’re unavailable for the coagulation cascade. Without calcium, the clotting factors can’t activate properly, and the clot does not form. This is why EDTA is used in many hematology tubes to preserve cells and prevent clotting. Magnesium binding isn’t the key for EDTA’s anticoagulant effect, thrombin isn’t neutralized by EDTA, and EDTA doesn’t promote platelet aggregation; removing calcium impairs the functions that would otherwise lead to clotting.

Calcium ions are essential cofactors for the steps that drive blood coagulation. EDTA keeps blood from clotting by binding calcium ions so they’re unavailable for the coagulation cascade. Without calcium, the clotting factors can’t activate properly, and the clot does not form. This is why EDTA is used in many hematology tubes to preserve cells and prevent clotting.

Magnesium binding isn’t the key for EDTA’s anticoagulant effect, thrombin isn’t neutralized by EDTA, and EDTA doesn’t promote platelet aggregation; removing calcium impairs the functions that would otherwise lead to clotting.