Blood Collection Tube Coagulation Sodium Citrate 3.2% or 3.8% Coagulation Sodium CitrateCoagulation tubes are used for examination of coagulation parameters. Coagulation tubes contain a buffered sodium citrate solution. It is available with a citrate concentration of 0.109 mol/l (3.2%) or 0.129 mol/l (3.8%). The mixing ratio is: 1 part citrate solution to 9