Bio Plus ESR Tube is mainly used for the test of blood coagulation mechanism. It is filled with buffered sodium
citrate solution, and citrate concentrations of either 0.109mol/l (3.2%) or 0.129mol/l (3.8%) are available.
The choice of the concentration depends upon the policies of the laboratories. Care for that soon after blood
sampling, mixing it 5-6 times by turning the tube 180°.