Order of Draw — Practice Checklist

Step-by-Step Procedure (8 steps)

1. 1.

   First: blood culture bottles (yellow/SPS or culture-specific bottles) — drawn first to maintain sterility before any other additive can be introduced.

2. 2.

   Second: light blue top (sodium citrate) — used for coagulation studies (PT, PTT, INR, fibrinogen).

3. 3.

   Third: red, red-speckled, or gold/SST (serum, no additive or clot activator with gel) — used for chemistry, lipid, and serology panels.

4. 4.

   Fourth: green top (sodium or lithium heparin) — used for stat chemistry and plasma-based tests.

5. 5.

   Fifth: lavender or pink top (EDTA) — used for CBC, differential, and blood bank testing.

6. 6.

   Sixth: gray top (potassium oxalate/sodium fluoride) — used for glucose and blood alcohol testing.

7. 7.

   Invert each tube immediately after filling, per that tube's required number of inversions (citrate 3–4, SST 5, heparin and EDTA 8–10) — never shake.

8. 8.

   If a blood culture is NOT ordered, the light blue citrate tube still goes first among the remaining tubes.

Instructor Competency Checkpoints (5)

Your instructor or preceptor will be watching for all of these during sign-off.

• States the six-tube sequence from memory without hesitation: blood culture → light blue → red/gold/SST → green → lavender/pink → gray.

• Correctly explains why the sequence exists (preventing additive carryover between tubes).

• Inverts each tube the correct number of times immediately after filling.

• Adjusts the sequence correctly when a blood culture is not ordered (starts with light blue).

• Never shakes a tube — uses gentle end-over-end inversion only.

Critical Mistakes — Avoid These

• ⚠

  Drawing the red/SST tube before the light blue citrate tube, which can carry clot activator into the coagulation tube and invalidate PT/PTT results.

• ⚠

  Shaking tubes instead of gently inverting them, which can cause hemolysis.

• ⚠

  Forgetting that blood cultures always come first, even before coagulation tubes, to protect sterility.

• ⚠

  Under- or over-inverting a tube relative to its required count.

• ⚠

  Confusing lavender/pink (EDTA, for CBC) with light blue (citrate, for coagulation) under time pressure.