What is a common anticoagulant used in blood collection tubes?

The correct choice, EDTA, is a widely used anticoagulant in blood collection tubes because it effectively chelates calcium ions in the blood. Calcium is a critical component in the coagulation cascade, and its removal helps prevent blood from clotting. This property makes EDTA particularly useful for hematological tests, as it preserves the shape and structure of cells, allowing for accurate cell counts and morphology assessments.

EDTA is also advantageous because it does not interfere with most cellular components, preserving the integrity of the sample for various laboratory analyses. Its commonly used concentration in blood collection tubes is usually in the form of disodium or tripotassium salts.

While other anticoagulants like citrate and heparin are also effective in preventing clot formation, their applications are typically specific to certain tests. Citrate is often used for coagulation studies, while heparin is more common in plasma and some specialized assays. Sodium fluoride, on the other hand, is primarily a glycolytic inhibitor and used alongside an anticoagulant to preserve glucose levels in blood samples rather than as a primary anticoagulant. Thus, EDTA stands out as the preferred anticoagulant for routine blood sample collection in hematology.