Color | Additive | Mode of Action | Uses |
Red Top | None | Blood clots, and the serum is seperated by centrifugation | Chemistries, Immunology and Serology, Blood Bank (Crossmatch) |
Purple Top | EDTA | Forms calcium salts to remove calcium | Hematolgy (CBC) and Blood Bank (crossmatch); requires full-draw -invert 8 times to prevent clotting and platelet clumping |
Light Blue Top | Sodium Citrate | Forms calcium salts to remove calcium | Coagulation tests (protime and prothrombin time), full draw required |
Green Top | Sodium heparin or lithium heparin | Inactivates thrombin and thromboplastin | For lithium level, use sodium heparin. For ammonia level, use sodium or lithium heparin |
Dark Blue Top | EDTA | Tube is designed to contain no contaminating metals | Trace elements testing (zinc, copper, lead, mercury) and toxicology |
Black Top | Sodium citrate (buffered) | Forms calcium salts to remove calcium | Westergren Sedimentation Rate; requires full draw |
Yellow-Black | Broth mixture | Preserves viability of microorganisms | Microbiology- aerobes, anaerobes, fungi |
Pink Top | Potassium EDTA | forms calcium salts | Molecular/viral load testing |
Light Green Top | Plasma Seperating Tube (PST) with Lithium heparin | Anticoagulates with lithium heparin; Plasma is separated with PST gel at the bottom of the tube | Chemistries |
Orange Top | thrombin | quickly clots blood | STAT serum chemistries |
Light Gray Top | Sodium flouride and potassium oxalate | Antiglycolytic agent preserves glucose up to 5 days | Glucoses, requires full draw (may cause hemolysis if short draw) |
Yellow | ACD (acid-citrate-dextrose) | complement inactivation | HLA tissue typing, paternity testing, DNA studies |
Gold Top | None | Serum seperator tube (SST) contains a gel at the bottom to seperate blood from serum on centrifugation | Chemestries, Immunology and Serology |
Light Brown Top | Sodium Heparin | Inactivates thrombin and thromboplastin; contains virtually no lead | Serum lead determination |