American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

What is the primary use of EDTA in blood sample collection?

1. To promote faster clotting

2. To prevent clotting

3. To stabilize glucose levels

4. To enhance cellular components

The correct answer is: To prevent clotting

EDTA, which stands for ethylenediaminetetraacetic acid, is primarily used in blood sample collection to prevent clotting. It works as an anticoagulant by chelating calcium ions in the blood, which are essential for the clotting process. By binding to these calcium ions, EDTA effectively inhibits the coagulation cascade, thereby ensuring that the blood remains in a fluid state for accurate analysis. This property is particularly important in various laboratory tests that require whole blood or plasma, as clotting can interfere with results and lead to inaccurate interpretations. Essential tests, especially hematological ones, rely on EDTA to maintain the integrity of the blood sample, allowing for reliable cell and component counting. The other options refer to processes that EDTA does not facilitate. It does not promote faster clotting, stabilize glucose levels in a meaningful way, or enhance cellular components in the manner described. Understanding the role of EDTA in blood sampling is crucial for laboratory procedures that require precise measurement and assessment of blood components.