Which statement about EDTA use in bone marrow samples is true?

Which statement about EDTA use in bone marrow samples is true?

• A. Slides must be prepared within 1 hour
• B. EDTA cannot be used for bone marrow samples
• C. Slides must be prepared within 24 hours
• D. EDTA preserves clotting time

Answer: (A)

Timely slide preparation after collecting bone marrow with EDTA is essential because cell morphology starts to change and artefacts appear soon after collection. EDTA acts as an anticoagulant by chelating calcium, which prevents clotting and helps keep the sample usable, but this protection is time-limited. If slides aren’t made quickly, within about an hour, changes such as cell distortion and lysis can compromise the accuracy of microscopic evaluation. Preparing within one hour gives the best chance to assess differential counts and cellular details reliably; waiting 24 hours increases artefacts and degrades diagnostic usefulness. EDTA is indeed suitable for bone marrow samples, and it does not “preserve clotting time” by extending it—rather, it prevents clotting by removing calcium.

Timely slide preparation after collecting bone marrow with EDTA is essential because cell morphology starts to change and artefacts appear soon after collection. EDTA acts as an anticoagulant by chelating calcium, which prevents clotting and helps keep the sample usable, but this protection is time-limited. If slides aren’t made quickly, within about an hour, changes such as cell distortion and lysis can compromise the accuracy of microscopic evaluation. Preparing within one hour gives the best chance to assess differential counts and cellular details reliably; waiting 24 hours increases artefacts and degrades diagnostic usefulness. EDTA is indeed suitable for bone marrow samples, and it does not “preserve clotting time” by extending it—rather, it prevents clotting by removing calcium.