Final answer:
Blood collected in a vacuum tube with EDTA is used for hematology testing because EDTA prevents clotting, which is necessary for tests like CBC and blood smears.
Step-by-step explanation:
Blood collected in a vacuum tube containing EDTA would be used for hematology testing. EDTA is a chelating agent that binds calcium ions, preventing the blood from clotting, which is essential for various hematological tests, including complete blood cell counts (CBC) and blood smears. These tests assist in diagnosing and monitoring various conditions such as anemia, infections, and hematological malignancies. In contrast, coagulation studies require non-anticoagulated blood and chemistry panels often use serum or plasma obtained after the blood has clotted. Immunological tests may require different types of preservatives or anticoagulants depending on the specific immune marker being assessed.