Blood Collection Tubes
There are several types of blood collection tubes, each containing different additives to preserve the blood for various tests:
Red Top Tube (no additive): Used for serum tests like cholesterol, glucose, and HIV.
Lavender/Purple Top Tube (EDTA): Contains ethylenediaminetetraacetic acid for complete blood counts (CBC), blood typing, and certain chemistries.
Light Blue Top Tube (sodium citrate): Used for coagulation tests, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT).
Green Top Tube (heparin): Contains heparin for plasma determinations in chemistry.
Gray Top Tube (sodium fluoride/potassium oxalate): Used for glucose testing as these additives inhibit glycolysis.
Yellow Top Tube (ACD or SPS): Contains acid citrate dextrose or sodium polyanethol sulfonate for blood culture and DNA testing.
These are the most common types, but there are variations and specialty tubes for specific tests and purposes.