Vacutainers/Blood tubes are widely used in clinical hematology and various blood cell detection instruments. The tubes use EDTA-K2 / EDTA-K3 as anticoagulant. At the same time, it has a comprehensive protective effect on blood, especially on platelets, which can effectively prevent the aggregation of platelets and keep the shape and volume of blood cells unaffected for a long time. EDTA tube can be used for direct sampling analyzer without actual opening. EDTA stands for Ethylene Diamine Tetra Acetic acid, the function of EDTA is to combine calcium in the blood and prevent blood coagulation.