EDTA Blood Collection Tube for Liquid Biopsy with Cell Protection

IV. Precautions

1. Collection Protocol

   • Gently invert tubes 5–10 times immediately after draw—do not shake—to prevent microclots.

   • Fill to marked volume: underfilling causes partial clotting; overfilling dilutes anticoagulant (causing pseudothrombocytopenia).

2. Sample Handling & Storage

   • Time Sensitivity: Prepare blood smears within 2 hours; whole blood stored ≤6 hrs (RT) or ≤4 hrs (4°C)—prolonged storage alters cell morphology.

   • Temperature: Ideal testing range: 18–22°C; extremes (>30°C or <15°C) affect cell volume.

3. Order of Draw
   Follow sequence: Blood culture → Plain tubes → Citrate coagulation tubes → EDTA tubes to avoid cross-contamination.

4. V. Frequently Asked Questions (FAQs)

5. Microclots observed post-collection. Solution?
   Cause: Inadequate/untimely mixing (especially at >25°C) or underfilled tube.
   Action: Invert ≥8 times; ensure precise fill volume.

6. EDTA-K₂ vs. EDTA-K₃: Key differences?

   • Form: K₂ = crystals; K₃ = liquid spray (faster dissolution).

   • Impact: K₃ overuse dilutes samples (falsely lowers Hb); K₂ offers better batch consistency.

7. Suitable for coagulation tests?
   No! EDTA chelates calcium, disrupting coagulation cascades. Use dedicated citrate tubes (blue cap) instead.

8. Causes/prevention of hemolysis?
   Causes: Blood impacting tube bottom, violent mixing, premature refrigeration (<30 min post-draw).
   Prevention: Angle tubes to let blood flow along walls; use large-bore needles; invert gently.

9. Preventing blood reflux infection?
   Procedure: After draw → Remove tube first → Release tourniquet → Withdraw needle. Prevents negative-pressure backflow.