Final answer:
The duty not included in a phlebotomist's traditional duties is performing tests on patient samples in the lab, which is the domain of medical technologists or clinical laboratory technologists.
Step-by-step explanation:
The traditional duties of a phlebotomist include correctly labelling all specimens with the required information, selecting the appropriate specimen containers for the specified test, and collecting the appropriate amount of blood by venipuncture or dermal puncture.
However, the duty that is not traditionally part of a phlebotomist's role is performing tests on patient samples in the lab. This task is typically within the scope of work for medical technologists (MTs) or clinical laboratory technologists (CLTs), who often hold a bachelor's degree and perform a wide variety of tests on various body fluids, including blood.