Different Blood Collection Tubes and Uses

When you are a phlebotomist, the very basic thing to consider is to familiarized yourself to the different collection tubes used in the laboratory and their corresponding uses.

• Yellow-topped tube: Sodium Polyethylene Sulfonate (SPS). For collection of blood cultures; aseptic technique for blood draw; invert tube 7-10 times to prevent clot formation.
• Red or gold serum separator tubes (SST); No anticoagulant. For collecting serum samples such as chemistry analysis. SST tubes should be gently inverted (completely, end over end) 5 times after collection to ensure mixing of clot activator with blood and clotting within 30 minutes. After the 30-minute period, centrifuge promptly at designated relative centrifugal force (rcf) for 15 ± 5 minutes to separate serum from cells. Serum can be stored in gel separator tubes after centrifugation for up to 48 hours. Do not freeze SST tubes. If frozen specimen is needed, separate serum into a labeled plastic transfer vial. Serum separation tubes must not be used to obtain therapeutic drug levels because the gel may lower the values.
• Red-topped (plain) tube: No anticoagulant, No additive. For serum chemistry, serology, blood bank, collection of clotted blood specimens
• Royal blue"topped tube": Without Ethylenediaminetetraacetic acid (EDTA) or Sodium Heparin (no anticoagulant blood will clot). For aluminum, arsenic, chromium, copper, nickel, and zinc levels; tube free of trace elements.
• Light blue"topped tube": With Sodium Citrate as anticoagulant (removes calcium to prevent clotting).For plasma-coagulation studies (eg, prothrombin times [PT]; PT/partial thromboplastin time [PTT] and factor assays). The tube must be allowed to fill to its capacity or an improper blood/anticoagulant ratio will invalidate coagulation test results. Invert tube 7-10 times to prevent clotting.
• Gold or Red Marbled "topped tube": Serum Gel Separator Tube (SST) For serum, used for most chemistry tests; these tubes should be gently inverted 5 times after collection to ensure mixing of clot activator with blood and clotting within 30 minutes. After 3-minute period, centrifuge promptly at designated rcf for 15 ± 5 minutes to separate serum from cells. Serum can be stored in gel separator tubes after centrifugation for up to 48 hours. Do not freeze SST tubes. If frozen specimen is needed, separate serum into a labeled plastic transfer vial. Serum separation tubes must not be used for therapeutic drug levels. The gel may lower values. Not for blood bank use.
• Light Green Marbled "topped tube": Gel Separator/Lithium, Heparin as anticoagulant.For potassium determination.
• Tan/Brown-topped tube: with heparin as anticoagulant. For heparinized plasma specimens for testing lead levels (ie, lead-free tube). Invert tube 7-10 times.
• Lavender-topped tube: with EDTA; removes calcium to prevent clotting. For whole blood and plasma, for hematology and complete blood counts (CBCs); prevents the filled tube from clotting. If the tube is less than half-filled, the proportion of anticoagulant to blood may be sufficiently altered to produce unreliable laboratory test results. Invert tube 6-8 times.
• Royal Blue "topped tube": no additive with EDTA or Sodium Heparin anticoagulant. For toxicology, cadmium and mercury: tube free of trace elements. Invert tube 7-10 times.
• Gray-topped tube: with Potassium Oxalate and Sodium Fluoride. For glucose levels, glucose tolerance levels, and alcohol levels.
• Plain pink tube: no additive or anticoagulant.For blood bank 
• Black tube: with Sodium Citrate (binds calcium). For Westergren sedimentation rate
• Green-topped tube: with anticoagulant Heparin (Sodium, Lithium, and Ammonium Heparin). For heparinized plasma specimens, plasma chemistries, arterial blood gases, and special tests such as ammonia levels, hormones, and electrolytes. Invert 7-10 times to prevent clot formation.