PPACK TFA is potent, selective and irreversible thrombin inhibitor. PPACK TFA can be used an alternative anticoagulant to lithium heparin (LiHep) for blood gas and whole-blood electrolyte analyses. PPACK TFA is also a plasminogen activator (rt-PA) inhibitor. PPACK TFA can inhibit the binding of rt-PA to plasma protease inhibitors.