Medical Laboratory Scientists (MLS) perform laboratory analyses to help the physician detect, diagnose and treat disease. Lab scientists work with sophisticated laboratory instruments and computers that must be kept in optimal operating condition to give the most accurate results. The volume and sophistication of laboratory testing will increase as the population ages. Physicians base about 70% of their diagnoses and treatment decisions on the results of laboratory testing. Medical Laboratory Scientists work under the supervision of a medical laboratory director in such departments as blood bank, clinical chemistry, microbiology, hematology, immunology, phlebotomy, body fluid analysis, and molecular testing.