Blood samples, color coding of The Test Tubes

Color coding of The Test Tubes

Stopper tube	Additives	Outcome of additive	Purpose of use
Red	None	For serum	Chemistry Serology Blood banking
Lavender	EDTA	Anticoagulant for plasma Remove calcium and prevent clotting	CBC CEA Best for hematology
Orange	Thrombin	Accelerate clotting usually in 5 minutes, for serum formation Should be inverted 8 times	All serum tests Chemistry
Light Blue	Sod. citrate	anticoagulant binds calcium. Get blood or plasma	Coagulation studies PT, APTT, factor assay
Gray	Na fluoride/K oxalate	Inhibit glycolysis Anticoagulant, remove Ca⁺⁺ to prevent clotting Get whole blood or plasma	Glucose GTT Lactate
Green	Na+ Heparin Lithium Heparin Ammonium Heparin	Inhibit thrombin activation to prevent clotting. Get whole blood or plasma	Ammonia, Carboxy Hb Lead Plasma chemistry
Yellow	Na⁺polyanetholesulfate	Prevent blood from clotting Stabilize bacterial growth Invert the tube 8 times to prevent clotting	Blood culture
Glod	Gel-separator Clot activator	Clot activators shorten the time for clot formation The gel forms a separator between cells and serum Invert the tube 5 times and centrifuge after the clot formation	Most chemistry tests Not good for blood banking
Light green	Gel separator Lithium heparin	Heparin prevents clotting The gel prevents cell contamination	Potassium determination
Black	Na ⁺ citrate	Binds Ca⁺⁺ 4:1 ratio of blood to anticoagulant	Westgreen ESR