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How to Become a Clinical Laboratory Scientist (CLS)

There are several pathways available to those who want to become clinical laboratory scientists (CLSs). The specific requirements vary by state and by the type of professional certification that may be required by employers. In most cases, CLSs are required to hold a bachelor’s degree and to complete an academic training program accredited by the National Accrediting Agency for Clinical Laboratory Sciences (NAACLS). There are several ways to meet this requirement, including bachelor’s degree programs with a dedicated clinical laboratory science or medical technology major, and bachelor’s degree completion programs that are designed to provide medical laboratory technicians (MLTs) who hold an associate degree with the additional coursework and training necessary to become medical laboratory scientists (MLSs). There are also post-baccalaureate MLS programs that are designed to provide students who hold a bachelor’s degree in a field other than clinical laboratory science or medical technology with the training necessary to become a CLS.

In addition to holding a minimum of a bachelor’s degree or a post-baccalaureate certificate from an NAACLS-accredited program, most employers and 11 states require CLSs to apply for licensure after earning a professional credential, the most common of which is the Medical Laboratory Scientist (MLS) certification offered by the American Society for Clinical Pathology (ASCP). CLSs may also be certified by two other nationally recognized organizations: American Medical Technologists (AMT), and the American Association of Bioanalysts (AAB). Licensure requirements for CLSs vary by state and individual employers have discretion over which certifications they may require or prefer for specific clinical and medical laboratory positions.

The professional certifications for CLSs offered by the ASCP, AMT, and the AAB require candidates to have a minimum of one year of full-time experience in a clinical laboratory, which can be accomplished through work as a medical laboratory technician (MLT) or a medical laboratory assistant (MLA). MLTs typically receive their training in associate degree programs or in professional certification programs, while working as an MLA only requires a high school education and supervised, on-the-job training. MLTs and MLAs who have a year or more of qualifying clinical experience in a medical laboratory are generally eligible to become CLSs once they have completed a bachelor’s program with an NAACLS-accredited curriculum in medical technology/medical laboratory science.

Training in Clinical Laboratory Science

Medical laboratories are typically housed within departments of pathology at hospitals, clinics, and other patient treatment facilities. These laboratories are responsible for performing a wide range of diagnostic testing procedures on blood, urine, and other biological specimens and supplying physicians, nurses, and other members of a medical team with reliable test results. Doing this type of work requires technical knowledge of medical testing equipment and familiarity with proper protocols for conducting various types of tests, as well as a foundational understanding of the underlying science. To achieve this balance of technical and theoretical knowledge, CLSs study biology and clinical chemistry extensively, take specialized courses in bacteriology, hematology, immunology, and virology, and complete supervised internships in medical laboratories.

CLS bachelor’s degree programs, which are commonly but not exclusively designated as Bachelor of Science (B.S.) in Medical Technology and/or Clinical Medical Science programs, are structured to incorporate approximately one year of clinical experiences. There are several ways in which this is achieved. One typical model provides students with three years of introductory and upper-division coursework in chemistry, biology, and health sciences, followed by a year of clinical internships. Another common model involves having students complete two years of lower-division coursework followed by two years in which students spend half of their time taking upper-division courses and the other half in clinical internships.

There are also pathways that allow students who are not enrolled in a bachelor’s degree program with a CLS or MLS curriculum to receive the training required to become a clinical laboratory scientist/medical technologist without having to repeat undergraduate courses. Students who hold a bachelor’s degree in a health science discipline that includes substantial coursework in biology and chemistry may be eligible for post-baccalaureate CLS/MLS certificate programs that provide one year of upper-division coursework and internship experiences.

In addition, graduates from associate degree programs in health and laboratory science may be eligible for a CLS/MLS completion program, some of which require applicants to hold an MLT certification. A completion program allows students to finish their bachelor’s degree requirements without having to repeat the coursework and internship hours that are part of an associate degree program.

Thus, the three most common ways to receive the academic training required to become a CLS and qualify for professional certification and then for licensure in the states that require it are as follows:

  • Earn a bachelor’s degree from a regionally accredited college or university with an NAACLS-accredited major or concentration in medical or clinical laboratory science/medical technology and a year of clinical internships.
  • Complete an associate degree program for clinical laboratory technicians and then enroll in an NAACLS-accredited MLT-to-MLS bachelor’s degree completion program.
  • Earn a bachelor’s degree in the health sciences from a regionally accredited college or university and then enroll in an NAACLS-accredited post-baccalaureate MLS training program.

CLS Certifications and Licensure

There are currently 11 states that require clinical and medical laboratory scientists to be licensed: California, Florida, Georgia, Hawaii, Louisiana, Montana, Nevada, New York, North Dakota, Tennessee, and West Virginia. While licensure requirements vary by state, most states require CLSs to hold a bachelor’s degree or the equivalent from an NAACLS-accredited program and many require CLSs to be credentialed by the ASCP, AMT, or the AAB.

The ASCP has an MLS certification for general practice CLSs, as well as several more specialized credentials for CLSs with advanced training in phlebotomy, blood banking, cytogenics and cytotechnology, hematology, microbiology, molecular biology, and other areas of clinical laboratory science. The AMT’s Medical Technologist (MT) credential is considered roughly equivalent to the ASCP’s MLS certification. The AAB offers an MT certification that has different requirements than AMT’s MT certification and that allows candidates who do not hold a bachelor’s degree to attain certification if they meet other requirements.

Graduates from bachelor’s programs, bachelor’s completion programs, and post-baccalaureate certificate programs accredited by the NAACLS generally meet the eligibility requirements to sit for the ASCP’s general-practice MLS certification exam, provided they have at least one year of clinical laboratory experience. Students who graduate from a bachelor’s program with a major in health sciences and who have substantial coursework in biology and chemistry can qualify to sit for a certification exam by completing an NAACLS-accredited MLS training program or by working for several years as a medical laboratory assistant or technician.

There are also pathways to certification for candidates with a bachelor’s degree who hold a Medical Laboratory Assistant or a Medical Laboratory Technician certification from the ASCP. Medical laboratory assistants and technicians who have two to four years of qualifying clinical experience can qualify for MLS certification. AMT and the AAB have similar requirements for MT certification, although the AAB will allow candidates for MT licensure who hold an associate degree in in laboratory science or medical technology to sit for its MT Basic Knowledge certification exam.

For more information on CLS certification refer to our What is CLS Certification and Is Certification a Requirement for Clinical Laboratory Scientists (CLSs)? FAQ.

Steps to Becoming a Clinical Laboratory Scientist

As noted above, becoming a CLS generally requires a bachelor’s degree with substantial coursework in biology, chemistry, and health sciences, a minimum of one year of clinical training, and a passing score on a certification exam offered by the ASCP, AMT, or AAB. There are several different pathways to accomplishing these objectives, and specific steps may depend on state licensing requirements and the type of experience and certification required by particular employers. The steps listed below provide a general overview of the most common routes taken by those who wish to become a CLS, MLS, or MT.

  1. High School Education: Graduate from high school or obtain a high school equivalency diploma with coursework in biology, chemistry, and mathematics courses in preparation for undergraduate coursework in medical technology and medical laboratory science or on-the-job training as a medical laboratory assistant.
  2. Postsecondary Education: Complete an NAACLS-accredited associate degree program for medical laboratory technologists followed by an MLT-to-MLS bachelor’s completion program; or complete an NAACLS-accredited bachelor’s degree program in medical technology or medical laboratory science; or complete a bachelor’s degree program with a major in biology, chemistry, or health sciences (or complete a minimum of 32 semester hours of coursework in chemistry, biology, and health sciences) followed by an NAACLS-accredited post-baccalaureate certificate program.
  3. Clinical Experience: Accrue a minimum of one year of supervised clinical experience as a medical lab assistant, a medical lab technologist, and/or a student intern in an NAACLS-accredited degree or certificate program at the associate, bachelor’s, or post-baccalaureate level.
  4. Professional Certification: Researching ASCP, AMT, and AAB certification requirements, prepare for and pass the appropriate certification exam, and receive a CLS or an MT credential.
  5. Licensure: CLSs and MTs who intend to practice in one of the 11 states that currently require licensure must apply for a license through the licensing board in their state of residence after completing the academic and professional training requirements set by the licensing board.

More information on clinical laboratory science certifications and certification requirements is available from the ASCP’s Board of Certification, the AAB’s Board of Registry, and AMT.

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