What Is a Medical Laboratory Scientist?

Medically Reviewed by Carol DerSarkissian, MD on July 10, 2023
3 min read

A medical laboratory scientist (MLS), also known as a medical technologist or clinical laboratory scientist, works in a medical laboratory analyzing a variety of biological specimens. They are responsible for performing scientific testing on samples from patients and reporting the results to doctors.

Medical laboratory scientists are trained to use sophisticated equipment like microscopes, hematology analyzers, and incubators. The data they find plays an important role in identifying and treating diseases like cancer, diabetes, and other medical conditions.

About 60% to 70% of decisions regarding your diagnosis, treatment, hospital admission, and discharge are based on the results of the medical laboratory scientist’s work.

Medical laboratory scientists are like the detectives of the healthcare world. They look for clues that can shed light on the diagnosis and treatment of a disease or injury.

They work closely with doctors and other medical laboratory technicians to diagnose and monitor diseases. They also assess how well any therapies and medications work. Areas of medical laboratory training include:

  • Chemistry
  • Hematology (the study of blood)
  • Immunology
  • Microbiology
  • Molecular diagnostics toxicology
  • Transfusion medicine (the study of the use of blood to treat or prevent diseases)

Medical laboratory scientists have a wide variety of responsibilities and duties. They can:

  • Cross-match blood for transfusion
  • Create quality assurance programs to monitor and ensure the accuracy of test results
  • Examine and analyze blood, body fluids, tissues, and cells
  • Monitor patient outcomes
  • Perform tests to look for abnormal cells 
  • Oversee the work of other medical laboratory technicians
  • Give test results to doctors
  • Use microscopes, cell counters, and other high-precision lab equipment

In order to become a medical laboratory scientist, students should complete either an associate degree program that includes general education, science, and medical laboratory science courses or a shorter certificate program that focuses on technical courses.

Next, they’ll enroll in a medical laboratory technician curriculum at a college or university. It should address each of the major laboratory disciplines, focusing on the theoretical and practical aspects of the practice.

Medical laboratory scientists complete a baccalaureate degree program that includes more in-depth courses than the technician classes, as well as management and education courses. They can also get a bachelor’s degree in a science or health-related field (like chemistry or microbiology).

Students will complete a clinical laboratory program or internship through a hospital-based program. These programs usually last five to six months.

Next they need to pass an exam given by the National Accrediting Agency for Clinical Laboratory Sciences (NAACLS). This would certify them as a medical technologist (MT), clinical laboratory scientist (CLS), or medical laboratory scientist (MLS).

Masters and doctoral programs are also available in medical laboratory science.

While you won’t directly see a medical laboratory scientist, chances are high that one will check any samples from your body taken during a doctor or hospital visit.

A medical laboratory scientist, for example, measures blood cholesterol and blood sugar, tests for anemia, checks your urine for protein, identifies strep throat bacteria, and prepares blood for transfusion.

Although they don’t spend as much time with you as doctors and nurses, medical laboratory scientists are just as dedicated to your health and well-being. They’re vital members of the healthcare team and play a critical role in collecting the information needed to give you the best possible care.