TUVAC tube interior is spray dried with 1.2 mg – 2.0 mg anhydrous EDTA / 1 ml blood. EDTA binds calcium ions and thus blockades the coagulation cascades. The tube contains either Dipotassium EDTA or Tripotassium EDTA. EDTA tubes are used for direct sampling analysis since erythrocytes, leucocytes and thormbocytes are stable in the EDTA anticoagulated blood for 24 hours. Blood smearing should be done within 3 hours after blood collection. GVT EDTA tubes can be used for testing whole blood in the clinical chemistry.
TUVAC coagulation tubes contain buffered Tri-sodium Citrate solution citrate concentration of either 0.109 mol/L (3.2 %) or 0.129 mol/L (3.8%) are available. The choice of the concentration depends upon the policies of the laboratories. The mixing ratio is 1 part citrate to 9 parts blood citrate is the standard anti coagulant for coagulation tests it prevent blood coagulation by binding Ca++ ions.
TUVAC tubes with Gel contain a barrier polymer gel in the base of the tube. The specific gravity of this material can make the barrier gel move upward to the serum. This Gel forms a stable barrier between the serum and blood cells. This barrier provides stability of certain parameters of the tubes under the recommended conditions for up to 48 hours before moving to the secondary tubes.