Tube cap color or type in order of draw |
Additive |
Usage and comments
|
Blood culture bottle |
Sodium polyanethol sulfonate (anticoagulant) and growth media for microorganisms |
Usually drawn first for minimal risk of contamination.[1] Two bottles are typically collected in one blood draw; one for aerobic organisms and one for anaerobic organisms.[2]
|
Light blue
|
Sodium citrate (weak calcium chelator/anticoagulant) |
Coagulation tests such as prothrombin time (PT) and partial thromboplastin time (PTT) and thrombin time (TT). Tube must be filled 100%.
|
Plain red
|
No additive |
Serum: Total complement activity, cryoglobulins
|
Gold (sometimes red and grey "tiger top"[3])
|
Clot activator and serum separating gel[4] |
Serum-separating tube: Tube inversions promote clotting. Most chemistry, endocrine and serology tests, including hepatitis and HIV.
|
Dark green
|
Sodium heparin (anticoagulant) |
Chromosome testing, HLA typing, ammonia, lactate
|
Light green
|
Lithium heparin (anticoagulant) |
Plasma. Tube inversions prevent clotting
|
Lavender ("purple")
|
EDTA (chelator / anticoagulant) |
Whole blood: CBC, ESR, Coombs test, platelet antibodies, flow cytometry, blood levels of tacrolimus and cyclosporin
|
Pink
|
EDTA (chelator / anticoagulant) |
Blood typing and cross-matching, direct Coombs test, HIV viral load
|
Royal blue
|
EDTA (chelator / anticoagulant) |
Trace elements, heavy metals, most drug levels, toxicology
|
Tan
|
EDTA (chelator / anticoagulant) |
Lead
|
Gray
|
|
Glucose, lactate[6]
|
Yellow
|
Acid-citrate-dextrose A (anticoagulant) |
Tissue typing, DNA studies, HIV cultures
|
Pearl ("white")
|
Separating gel and (K2)EDTA |
PCR for adenovirus, toxoplasma and HHV-6
|