Phlebotomy · Study guide

Order of draw: tube colors, additives and tests

The phlebotomy order of draw in one chart, with each tube's additive, common tests, inversion counts and an easy memory trick.

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Order of draw chart

#Tube / bottleAdditiveCommon testsInversions
1Blood culture bottles / yellow SPSBroth media / SPSBlood culturesPer manufacturer
2Light blueSodium citratePT/INR, PTT and other coagulation tests3–4
3RedClot activator (plastic) or none (glass)Serum chemistry, serology5 (plastic)
4Gold / red-gray (SST)Clot activator + gel separatorChemistry panels5
5Green / light green (PST)Heparin (+ gel in PST)STAT and plasma chemistry8–10
6Lavender / pinkEDTACBC (lavender); blood bank (pink)8–10
7GraySodium fluoride / potassium oxalateGlucose, lactic acid8–10

Based on the CLSI order of draw. Inversion counts vary by manufacturer; follow the tube maker's instructions and your facility's policy.

Easy way to remember it

"Stop Light Red, Stay Put, Green Light Go": Sterile (cultures), Light blue, Red, SST, PST, Green, Lavender, Gray.

Why the order matters

Additives can carry over from one tube to the next on the needle. EDTA from a lavender tube, for example, binds calcium and falsely raises potassium if it gets into a chemistry tube. Drawing in the standard order keeps results accurate.

Test yourself

Order of draw is one of the most-tested topics on the NHA CPT, ASCP PBT and AMT RPT exams. Take the free 50-question phlebotomy practice test →

Frequently asked questions

What is the order of draw for blood collection?

Blood cultures, light blue (citrate), red, gold SST, green (heparin), lavender (EDTA), then gray (fluoride).

Why is the light blue tube drawn before the red tube?

So clot activator from serum tubes can't carry over and affect coagulation results.

What goes first when using a butterfly for a light blue tube?

A discard tube, so air in the tubing doesn't underfill the citrate tube.

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