Final answer:
Hematology is the category of lab testing performed by the phlebotomy department, where phlebotomists draw blood for various tests such as hematocrit.
Step-by-step explanation:
The three lab test categories you asked about are key areas of medical laboratory testing. Among these, Hematology is the category that the phlebotomy department primarily performs. Phlebotomists are trained professionals in phlebotomy, skilled in drawing blood for tests, transfusions, donations, or research. Tests like hematocrit that measure the percentage of red blood cells in a blood sample are common examples of hematology tests that involve skills in phlebotomy. Phlebotomists may also perform a venipuncture to collect blood or a capillary stick when only a small quantity of blood is needed. Other categories that you mentioned, such as Microbiology and Clinical Chemistry, are also integral to medical laboratories but are typically beyond the primary scope of phlebotomists, who focus mainly on the collection of blood samples.