What is the primary purpose of using EDTA in blood samples?

The primary purpose of using EDTA (ethylenediaminetetraacetic acid) in blood samples is to prevent clotting. EDTA works as an anticoagulant by binding calcium ions in the blood, which are necessary for the coagulation process. Without calcium, the clotting cascade cannot initiate, allowing the blood to remain in a liquid state for accurate laboratory analysis.

This is crucial for various hematological tests where it is essential to analyze blood cells in their liquid form. For example, complete blood counts (CBCs) rely on whole blood, and any clotting would affect the results, leading to inaccurate cell counts and other parameters. Therefore, the use of EDTA ensures that the sample can be processed and analyzed effectively without the interference of clot formation.