Which anticoagulant is preferred for conducting a WBC differential?

The preferred anticoagulant for conducting a white blood cell (WBC) differential is EDTA. This choice is primarily because EDTA effectively chelates calcium, which is essential for the blood clotting process. By preventing clot formation, EDTA preserves the morphology and characteristics of blood cells, allowing for accurate analysis during a differential count.

Additionally, EDTA does not interfere with the staining of cells, making it suitable for microscopic evaluation of blood smears. Its ability to maintain cellular integrity while providing an accurate representation of the WBC population is crucial for diagnostic purposes.

Heparin, while also an anticoagulant, can affect the appearance of the cells and may not provide the same clarity for differential counts. Citric acid and sodium citrate are typically used for coagulation studies rather than hematological evaluations, making them less suitable for obtaining a WBC differential. Therefore, EDTA is the most appropriate choice in this context.