Order of Draw, Tube Color Variations & EDTA Emphasis

Order of Draw – General Concept

  • Instructor emphasizes that understanding the order of draw is crucial (“could all go into a ladder”).

  • Key laboratory analyses mentioned:

    • Complete blood counts (CBCs)

    • Finger‐stick collection considerations

    • ABO blood type and screen (T&S)

Tube Color Specifics Discussed in the Clip

  • Pink‐top tubes

    • Many hospitals assign pink to blood bank studies (ABO, Rh, type & screen, cross‐match).

    • Some institutions originally lacked pink tubes; they adopted them later to standardize.

  • Gold‐top (SST) vs. Tiger‐top (SST) tubes

    • LabCorp reportedly “hates” gold‐tops; they prefer tiger‐tops or “labradors” (likely a verbal slip meaning Lab‐draw SST).

    • Despite LabCorp’s dislike, gold‐tops are still kept in some facilities for special purposes.

  • Heavy‐metal testing tubes

    • Instructor notes heavy metals often use EDTA as an anticoagulant.

    • Although heavy metal protocols will not be covered in detail today, the point is flagged for future study.

  • Gray‐top tubes

    • Mentioned as the next topic to be addressed (no details given in the clip).

    • Gray tops usually contain sodium fluoride/potassium oxalate for glucose or lactate testing (implied knowledge).

Institutional Variation & Clinical Expectations

  • Students must ask each clinical site what supplies they stock because:

    • Inventory differs by hospital, clinic, or reference lab.

    • Color choices (e.g., pink vs. lavender for blood bank work) vary.

    • Some sites may omit certain tubes entirely (e.g., LabCorp seldom uses gold‐tops).

  • Critical thinking exercise suggested:

    • When you arrive at clinical, challenge yourself to list the tubes available and map them to the standard order of draw.

    • Understand substitutions (e.g., tiger‐top for gold‐top) while maintaining additive compatibility.

EDTA Emphasis

  • EDTA is repeatedly highlighted:

    • Standard lavender and pink tubes contain K2/K3‐EDTA.

    • EDTA is also the additive used for many heavy‐metal assays, counter to the common assumption they might require royal‐blue (trace‐element) tubes.

  • Takeaway: Always verify additive requirements, not just color.

Practical / Ethical / Safety Points

  • Proper tube choice ensures sample integrity, patient safety, and valid results.

  • Failing to follow the correct order of draw can cause additive carryover, potentially producing erroneous results or patient harm.

Quick Reference – Mentioned Tube Colors & Typical Additives

  • Pink – K2K_2 EDTA; blood bank.

  • Lavender – K<em>2K<em>2/K</em>3K</em>3 EDTA; CBC, ESR.

  • Tiger‐top – Clot activator + gel (SST).

  • Gold – Clot activator + gel (SST).

  • Gray – NaF/KOxNaF/K_Ox (sodium fluoride/potassium oxalate) or NaF/Na2EDTANaF/Na_2EDTA; glucose/lactate.

Suggested Follow-Up Study Topics

  • Detailed heavy‐metal collection protocols.

  • Full order‐of‐draw mnemonic (e.g., “Boys Love Ravishing Girls Like Dieters Love Greek Yogurt”).

  • Additive mechanisms (chelators vs. anticoagulants vs. preservatives).