Performs medical laboratory tests, procedures, experiments, and analyses to provide data for diagnosis, treatment, and prevention of disease: conducts chemical analyses of body fluids, such as blood, urine, and spinal fluid, to determine presence of normal and abnormal components. Studies blood cells, their numbers, and morphology, using microscopic technique. Performs blood group, type, and compatibility tests for transfusion purposes. Analyzes test results and enters findings in computer.