The small, delicate veins of many companion pets pose venous blood collection challenges. Pre-evacuated tubes can easily collapse fragile veins, while a gentler collection with a syringe requires a transfer and can result in insufficient sample quality. The innovative S-Monovette multi-sampling, closed blood collection system provides a choice of collection technique to accommodate varying vein conditions. • Lithium Heparin- Heparin, at an average concentrate of 16 I.U./ml, is used as an anticoagulant for plasma generation. Heparin is coated onto beads which forma layer between the plasma and the corpuscular components during centrifugation. This function of the plasma gel is identical to serum-gel.