It has an ability to chelate 2 valance of metal ion. Therefore it interrupts the
coagulation by removing Ca2+ ion. Approximately 1mg of EDTA is used for 1mL of blood.
Since it does not harm the blood cell or any coagulation factor except Ca2+ ion, this
anti-coagulant is preferably used in CBC.
EDTA is the acidic and it has the ability to chelate the positive metal ion, this is not
preferred to use in the blood gas analysis. If this anti-coagulant is used for blood gas
analysis, you may encounter the low ISE parameter (pH and electrolytes).