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Intermediate Technical IVT

EDTA

Pronunciation: E-D-T-A

Also written as: EDTA — Ethylenediaminetetraacetic acid

Ethylenediaminetetraacetic acid, an anticoagulant additive used in blood collection tubes to prevent clotting.

Full Definition

EDTA is a chelating agent that prevents blood coagulation by binding calcium ions, which are essential for the clotting cascade. It is commonly used in lavender-top tubes for hematology testing, including complete blood counts (CBC) and blood smears. EDTA preserves cellular morphology and prevents platelet aggregation, making it ideal for automated cell counting. The anticoagulant must be properly mixed with blood samples immediately after collection to prevent microclot formation. Different concentrations (K2EDTA, K3EDTA) may be specified depending on the test requirements.

Usage

Usage note: Always specify the type (K2EDTA, K3EDTA) when documenting tube selection

In Context

  • "The CBC specimen was collected in a 3mL K2EDTA tube and inverted eight times for proper mixing." — Laboratory collection protocol
  • "EDTA contamination in the chemistry sample caused spuriously low calcium results." — Quality control report

Also known as

EDTA anticoagulant

Contrasted with

coagulant

Don't confuse with

heparin citrate

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