A medical laboratory technologist / medical laboratory scientist / clinical laboratory technologist is a healthcare professional who performs chemical, hematological, immunologic, histopathological, cytopathological, microscopic, bacteriological diagnostic analysis on body fluids as well as other specimens. Medical laboratory scientists work in clinical laboratories at hospitals, reference labs and nonclinical industrial labs.

Most Medical Laboratory Technologists are generalists skilled in all areas of the clinical laboratory. However, some opt for specialization later and undergo additional training to perform more complex analysis than usual within a specific field. These specialties include clinical biochemistry, hematology, coagulation, microbiology, bacteriology, toxicology, virology, parasitology, mycology, immunology, immunohematology (blood bank), histopathology, histocompatibility, cytopathology, genetics, cytogenetics, electron microscopy and IVF labs.

Medical laboratory technologists work in all areas of the clinical laboratory, including blood banking, chemistry, hematology, immunology, histology and microbiology . They perform a full range of laboratory tests – from simple prenatal blood tests to more complex tests to uncover diseases such as HIV/AIDS, diabetes, and cancer. They are also responsible for confirming the accuracy of test results, and reporting laboratory findings to pathologists and other physicians. The information that a medical laboratory technologist gives to the doctor influences the medical treatment a patient will receive. Medical laboratory technologists operate complex electronic equipment, computers, and precision instruments costing millions.