Free tool
Look up a collection tube by color, additive or test. Type a test name such as CBC, PT/INR or glucose, or a color such as lavender, and see the additive, the typical use and where the tube falls in the order of draw.
Built for NHA CPT exam prepStopper colors vary a little by manufacturer; the additive is the fact to learn. The order-of-draw step shows the standard six-step CLSI sequence; tubes without a step are not part of it, so follow your lab's chart.
Tube colors are pure recall, which is what spaced repetition is best at. Encodr schedules them until they stick.
Get started freeStart from the test: a PT/INR or aPTT is a coagulation test and goes in a light blue sodium citrate tube that must be filled to the line; a CBC goes in lavender EDTA; glucose, lactate and blood alcohol go in gray because fluoride blocks glycolysis. Serum chemistry uses red or gold tubes with a clot activator, and green heparin tubes give plasma for chemistry. Pink (EDTA for blood bank), yellow ACD (genetic and HLA testing), royal blue (trace metals), tan (lead) and black (Westergren ESR) are the specialty tubes.
Once you know the tube, practice where it sits in the sequence with the order of draw quiz, then work through the NHA CPT phlebotomy course, which teaches tube colors and additives in unit 6.
What each blood collection tube color means: the additive, the tests it is used for, and where it falls in the order of draw. A study reference for the NHA CPT exam.
The standard phlebotomy order of draw runs blood cultures, light blue, serum, green, lavender, gray. Why the sequence exists, what goes wrong when it is broken, and how to practice it.
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