Free tool

Order of Draw Quiz

Practice the standard order of draw. You get a random set of tubes; tap them in the order they should be filled, then check your sequence. It runs entirely in your browser.

Built for NHA CPT exam prep

Tubes for this draw

Tap the tubes in the order you would fill them.

Your sequence

    Result

    Put every tube in order, then press Check order.

    The order of draw is one of the most tested patterns on the CPT exam. Encodr drills it with spaced repetition until it is automatic.

    Get started free

    The standard order of draw

    1. Blood culture bottles (yellow SPS; aerobic bottle before anaerobic with a winged set)
    2. Light blue (sodium citrate)
    3. Serum tubes: red, and gold or red-speckled gel tubes
    4. Green (heparin)
    5. Lavender (EDTA)
    6. Gray (sodium fluoride and potassium oxalate)

    This is the CLSI sequence as republished by tube makers and hospital labs. It exists to stop additive from one tube being carried into the next on the needle or the stopper, and to keep sterile cultures from picking up stopper flora. For example, EDTA carried into a serum or heparin tube can raise potassium and lower calcium, and clot activator carried into a citrate tube can shorten coagulation times. Some lab charts add tubes (for example ACD and PAXgene) that are not in this six-step list, so follow your facility's chart on the job. The same order applies to a tube holder, a syringe transfer and a winged set. When a winged set is used and the first tube is a light blue, a discard tube clears the air in the tubing first.

    The quiz uses only the six steps above, and a serum tube stands for red or gold. For more on the exam itself, see the NHA CPT phlebotomy course, the tube color guide and the exam pass score calculator.

    From the blog

    The order of draw, explained

    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.

    Read →

    Phlebotomy tube colors and additives

    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.

    Read →

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