<Li> Ethylenediaminetetraacetic acid (EDTA) strongly and irreversibly chelates (binds) calcium ions, preventing blood from clotting . </Li> <Li> Citrate is in liquid form in the tube and is used for coagulation tests, as well as in blood transfusion bags . It binds the calcium, but not as strongly as EDTA . Correct proportion of this anticoagulant to blood is crucial because of the dilution, and it can be reversed with the addition of calcium . It can be in the form of sodium citrate or acid - citrate - dextrose . </Li> <Li> Oxalate has a mechanism similar to that of citrate . It is the anticoagulant used in fluoride oxalate tubes used to determine glucose and lactate levels . </Li>

Mechanism of action of citrate as an anticoagulant