Order of Draw: The Tube Chart, and a Trainer to Learn It

1. 1
   Blood culture bottles

   Culture broth (bottles) or SPS (yellow tube) · invert 8 to 10 times (SPS tube)

   Blood cultures
2. 2
   Light blue top

   Sodium citrate · invert 3 to 4 times

   PT/INR, aPTT, D-dimer, fibrinogen
3. 3
   Red top

   None (glass) or clot activator (plastic) · invert 5 times (plastic); none (glass)

   Serum chemistry, serology, drug levels
4. Gold top (SST)

   Clot activator and gel separator · invert 5 times

   Comprehensive metabolic panel, lipid panel, hCG, PSA, hepatitis antibodies
5. Orange top (RST)

   Thrombin-based clot activator · invert 5 to 6 times

   Serum chemistry when results are needed fast
6. 4
   Green top

   Sodium or lithium heparin · invert 8 to 10 times

   Ammonia (on ice), ionized calcium, lithium level (sodium heparin)
7. Light green top (PST)

   Lithium heparin and gel separator · invert 8 to 10 times

   STAT chemistry: electrolytes, BMP, troponin
8. 5
   Lavender (purple) top

   K2EDTA · invert 8 to 10 times

   CBC, hemoglobin A1c, ESR, BNP
9. Pink top

   K2EDTA · invert 8 to 10 times

   Blood type, antibody screen (blood bank)
10. 6
    Gray top

    Sodium fluoride and potassium oxalate · invert 8 to 10 times

    Lactate, blood alcohol, fasting and timed glucose

Order and inversions: BD Vacutainer Order of Draw for Multiple Tube Collections (VS5729-6, reflects CLSI H3-A5). Test examples: VCU Health Pathology, CLSI Order of Blood Draw Tubes and Additives (rev. 2/2025); which tube a test goes in varies by lab, so follow your facility's list. Checked October 27, 2026. certoutlook.com/phlebotomist/order-of-draw/

Order of draw trainer

Two drills. Put them in order gives you a random set of tubes from a requisition: tap them in the order you would fill them. Which tube? names a test and asks which tube it goes in.

Why each tube sits where it does

1. 1Blood cultures (Culture bottles). Drawn first so the sterile culture bottles cannot pick up contamination from another tube or its stopper.
2. 2Coagulation (Light blue). Comes before any serum tube so clot activator cannot carry over into the coagulation sample, and before heparin and EDTA, which are anticoagulants that would upset clotting results.
3. 3Serum (Red, Gold SST, Orange RST). Serum tubes come after citrate and before the heparin, EDTA and fluoride tubes, so none of those anticoagulants or preservatives reach the serum sample. EDTA carried into a serum tube raises potassium and lowers calcium.
4. 4Heparin (Green, Light green PST). Heparin comes after serum so it cannot stop a serum tube from clotting, and before EDTA and fluoride so their potassium and other additives stay out of the heparin chemistry sample.
5. 5EDTA (Lavender, Pink). EDTA goes late because potassium EDTA is the additive that does the most damage when it carries over: it falsely raises potassium and binds calcium, magnesium and zinc in the next sample.
6. 6Glycolytic inhibitor (Gray). Gray is last because sodium fluoride and potassium oxalate would interfere with many other tests if they carried into another tube.

Carryover effects: Biochemia Medica 2017;27(2): EDTA contamination and the order of draw; BD order of draw chart.

Three exceptions that show up on the exam

• Fingersticks use a different order. For capillary collections the CLSI order is blood gas first, then EDTA, then other additive tubes, with serum last. EDTA moves up because platelets start clumping almost at once in skin-puncture blood. (MLO, WHO)
• Butterfly plus a light blue tube first means a discard tube. With a winged set, draw a plain or coagulation discard tube first to fill the tubing's dead space, so the citrate tube gets the right blood-to-additive ratio. The discard tube does not need to be full. (BD)
• Your facility's manual wins. BD's own chart says to follow your facility's protocol for order of draw, and labs differ on which tube a test goes in (a STAT chemistry may go in light green where a routine one goes in gold).