ASCP (American Society for Clinical Pathology) Phlebotomy Technician Certification Practice Exam

The specimen collection tube commonly used for hematology tests is the tube containing EDTA (Ethylenediaminetetraacetic acid). EDTA acts as an anticoagulant, which prevents blood from clotting and preserves the cellular components of the blood for accurate analysis. Hematology tests often require an assessment of blood cells, including red blood cells, white blood cells, and platelets. To obtain reliable results, it is crucial that the blood remains in a liquid state, which is precisely what EDTA facilitates.

The use of EDTA is preferred for many hematology procedures because it maintains the integrity of blood cells and ensures that they do not aggregate or clot before testing. This quality is especially important in tests such as complete blood counts (CBC) and blood smears, where the evaluation of blood cell morphology and count is required.

In contrast, other tubes such as those with sodium citrate are primarily used for coagulation studies, serum separator tubes are utilized for tests that require serum (i.e., after allowing blood to clot), and heparin tubes are often reserved for certain biochemical tests and some specific hematological tests, but they are not the standard for general hematology evaluations. Each of these alternatives has its place in laboratory testing,