Blood Collection Tubes

About

Blood Collection Tubes Blood collection tubes are sterile, single-use vacuum tubes designed to safely collect venous blood for laboratory tests. Each tube contains a predefined vacuum and, if needed, a specific additive (anticoagulant, clot activator, preservative, or separator gel) tailored to the type of test. The vacuum passively draws blood into the tube once the patient’s vein is accessed, making collection safer and more convenient. Tubes are color-coded by cap shank (per ISO 6710) to indicate the additive inside. For example, light-blue tops hold sodium citrate (an anticoagulant for coagulation studies), lavender (purple) tops hold EDTA (a calcium-chelator for hematology), green tops hold heparin, and red or gold tops have no additive (or a clot activator plus gel) for serum chemistry tests. In short, the cap color “tells you exactly what additive is inside, and the additive determines what happens to the blood after collection”. Blood collection tubes (often called vacutainer tubes) are sterile glass or plastic tubes pre-filled with a vacuum. When venipuncture is performed, the vacuum draws a precise volume of blood into the tube. Each tube has a color-coded cap indicating which additive (if any) is inside. These additives (anticoagulants, clot activators, separating gels, or preservatives) stabilize the blood for specific laboratory tests. For example, anticoagulants like EDTA, citrate, or heparin prevent clotting so that plasma or whole blood can be tested; clot activators (silica particles) induce clotting to yield serum; and gels (in “separator” tubes) form a barrier between cells and serum after centrifugation Some tubes also contain preservatives (e.g. sodium fluoride) that inhibit metabolic reactions (such as glycolysis) to stabilize analytes like glucose. Types of Tubes (Color and Additive) Common blood collection tubes (with their typical additives and uses) include: Light Blue Top (Citrate) : Contains 3.2% sodium citrate anticoagulant. Used for coa