Lithium heparin PET tubes, also known as lithium heparin plasma tubes, are a type of blood collection tube used in medical settings for collecting blood samples. These tubes contain lithium heparin as an anticoagulant, which prevents the blood from clotting by inhibiting the action of thrombin and other clotting factors.Easy sample handling with loading capacity of 3 mL, 4 mL, 5 mL provide worry-free performance.