Vacutainer Blood Collection Used for routine clinical biochemistry tests, emergency biochemistry tests, some test items in blood rheology Product Details Vacutainer blood collection is a sterile glass or plastic test tube with a colored rubber stopper creating a vacuum seal inside of the tube, facilitating the drawing of a predetermined volume of liquid. Vacutainer tubes may contain additives designed to stabilize and preserve the specimen prior to analytical testing. Tubes are available with a safety-engineered stopper, with a variety of labeling options and draw volumes. The color of the top indicates the additives in the vial. application 1.Gold or "tiger" red/black top: clot activator and gel for serum separation 2. Red top (plastic, not glass): clot activator but no serum separation gel 3.Orange or grey/yellow "tiger" top: thrombin, a rapid clot activator, for stat serum testing