In larger labs they may just do cytotechnology. Cytotechnology is the study of cells. They may also do only histotechnology. This is the study of tissue. The type of tests performed, the level of judgment needed, and the amount of responsibility workers assume depends mostly on the amount of education and experience they have.
Medical technologists do complex tests.
They may evaluate test results, and develop and change ways of doing things. They may also establish and keep watch over programs to make sure that tests are accurate. Some medical technologists supervise laboratory technicians. Blood bank technologists collect, type, and prepare blood for transfusions. Technologists who prepare specimens and check the chemical and hormonal contents of body fluids are called clinical chemistry technologists.