What is the primary purpose of using potassium EDTA in blood collection tubes?

The primary purpose of using potassium EDTA in blood collection tubes is to prevent coagulation. EDTA (ethylenediaminetetraacetic acid) acts as an anticoagulant by binding to calcium ions in the blood. Calcium is a critical factor in the coagulation cascade, and by chelating calcium, EDTA effectively interrupts the process of clot formation. This ensures that the blood sample remains in a liquid state, allowing for accurate laboratory analysis of blood components without the interference of clotting.

When blood is collected in a tube containing potassium EDTA, the anticoagulant facilitates various tests that require the evaluation of blood cells, such as complete blood count (CBC) and blood smears. Maintaining the sample in a non-coagulated state is crucial for precise results and reliable diagnostic information.

The other options include concepts that are not aligned with the primary function of potassium EDTA. Notably, it does not enhance clotting or decrease viscosity, as those factors are unrelated to the anticoagulant properties of EDTA. Additionally, while potassium EDTA may assist in preparing a sample for swift analysis by preserving its state, the main role remains its capability to prevent coagulation.