... 2ml, 3ml, 4ml, 5ml, 6ml, 7mlTypes of Additives: Sodium Heparin, lithium HeparinMaximum Centrifuge Speed: 5000 turns/min.Maximum Vacuum Tolerance ... calcium due to the relative higher content of the heparin.3. Heparin Anti-coagulation Blood sample should be used within 6 ... after sampling, otherwise, the blood will coagulate again.. The heparin tubes are use to blood sampling in clinical biochestry, ...