CPT (Certified Phlebotomy Technician) Practice Exam

The presence of EDTA in the lavender tube is significant because EDTA (Ethylenediaminetetraacetic acid) acts as an anticoagulant. It prevents blood from clotting by binding calcium ions in the blood, which are essential for the coagulation process. This characteristic makes the lavender tube particularly useful for hematology tests, such as complete blood counts (CBC), where it is crucial to preserve the cellular components of blood in their original state for accurate analysis. In addition to its role in preventing clotting, the use of EDTA is well-established in laboratory settings, making it a preferred choice for many blood tests that require whole blood or plasma in a non-clotted state. This choice ensures the reliability and accuracy of test results, which is essential in medical diagnostics.