Medical Laboratory Scientist Certification – MLS (ASCP)

The medical laboratory scientist (MLS), sometimes referred to as a clinical laboratory scientist (CLS) or medical technologist (MT), performs a battery of highly specific analytical tests to assist doctors in reaching an accurate diagnosis regarding the patients who visit their office.

Due to the vital nature of this work, employment in this field is slated to rise significantly over the next decade; in fact, the Bureau of Labor Statistics (BLS 2023) predicts a 5 percent increase in jobs from 2022 to 2032, which equates to 16,800 new job openings and a growth rate that is faster than the three percent average for all occupations for the same decade.

Individuals interested in pursuing a career in this field must meet certain requirements before being eligible to obtain the Medical Laboratory Scientist (MLS) certification through the American Society for Clinical Pathology (ASCP), the primary certifying body for the profession. While certification isn’t a requirement nationwide, several states and territories require licensure or certification to practice, including California, Florida, Georgia, Hawaii, Louisiana, Montana, Nevada, New York, North Dakota, Puerto Rico, Rhode Island, Tennessee, and West Virginia.

Preparation for becoming a medical laboratory scientist begins well before the individual sits for the exam through the ASCP; it can start as early as high school, where potential lab scientists will want to take as many lab-based science classes as possible to help prepare for the rigors of the MLS college curriculum and the difficulty of the certification exam. By starting the process as early as possible, an aspiring medical laboratory scientist can get a feel for lab work and build the necessary educational foundation to enter the profession and succeed in the role.

Auburn University of Montgomery
University of West Florida
Grand Canyon University

Early Preparation in High School to Become an MLS

As mentioned, an aspiring medical lab scientist should first take relevant courses during high school that will prepare the student for later schooling and professional work. This may include biology, chemistry, math, and other sciences courses. Preparation should continue outside of the classroom as well.

For example, an aspiring medical laboratory scientist can consider searching for volunteer opportunities with local professionals to achieve clinical volunteer experience and better understand the job’s scope and rigors. Remaining diligent during this time will help the student prepare for college, the certification exam, and life as a medical laboratory scientist.

MLS (ASCP) Certification Preparation

Those working as medical laboratory scientists must complete a four-year bachelor’s degree through an accredited college or university before they can sit for the certification exam through ASCP. Furthermore, ASCP provides that such students, during college or university, should take mathematics, chemistry, and biology classes, which will help them prepare for the exam and the career requirements.

The most expeditious route to earning the MLS certification is to ensure that one’s bachelor’s degree program in medical laboratory science is accredited by the National Accrediting Agency for Clinical Laboratory Sciences (NAACLS). Successfully completing a NAACLS-accredited program qualifies the student to sit for the MLS (ASCP) certification exam within five years of graduation. Graduates of other programs may also be eligible but must meet additional requirements, including experience requirements that can add significantly to the timeline for becoming certified.

That said, individuals do have the option of obtaining eligibility via several different routes. For individuals who have not completed a NAACLS-accredited medical laboratory science program, the available routes to certification include completing a bachelor’s degree with sufficient coursework in biological sciences and chemistry and one of the following:

  • Earn a medical laboratory technician MLT (ASCP) certification and complete two years of qualifying clinical laboratory experience
  • Gain five years of full-time acceptable clinical laboratory experience
  • Hold a now-discontinued CLA (ASCP) certification and complete four years of qualifying clinical laboratory experience
  • Complete a 50-week U.S. military medical laboratory training course and have one year of work experience
  • Hold an MT/MLS (ASCP) certification and have five years of qualifying lab experience.

Sometimes, a student may find that his or her eligibility overlaps among these categories, which is not a cause for concern. As long as an applicant can fit squarely within one of the sets of requirements, they are eligible to sit for the certification exam offered by ASCP to become a medical laboratory scientist. If a student is missing one or more of the eligibility requirements to become certified, they should first achieve that before moving any further with ASCP.

MLS (ASCP) Certification Exam Preparation

Upon meeting all of the eligibility requirements to become certified as a medical laboratory scientist through ASCP, the individual should decide when to sit for the certification exam and begin to research what to expect on the test day. As with most exams, the better prepared the test-taker is on exam day, the more likely they will get the results they want.

There is no one specific method of study that will guarantee success on the MLT exam. That said, there are certain ways to prepare, some of which are suggested by ASCP itself, that can help bolster an individual’s chances of succeeding on the exam and ultimately becoming certified.

Perhaps most importantly, the individual should read through the publications on the ASCP “suggested reading list” for aspiring medical laboratory scientists. An abridged list is included below:

Those interested in pursuing a certification as a medical laboratory scientist should understand that this is only a portion of a suggested reading guide prepared by ASCP. As such, anyone who wishes to work in this field should make a point to read as much relevant material as possible to ensure adequate preparation for the exam.

Along with a suggested reading list, ASCP also provides an overview of the contents of the certification exam for students to use while preparing. While the contents overview does not list the exact questions that students will encounter, it offers a comprehensive list of topics with which students should familiarize themselves before exam day and the weight each subject will have on the test. According to the ASCP website, the subjects that will be found on the certification examination, as well as their descriptions, are listed below:

  • Blood bank (BBNK) – blood group systems, antibody screen & identification, crossmatch, DAT, elution/adsorption, blood donation, transfusion therapy, transfusion reactions, HDFN, phenotyping/genotyping, antibody titer, pre-warm technique
  • Urinalysis and other bodily fluids (UA) – physical, chemical & microscopic urinalysis and body fluid analysis (CSF, amniotic, synovial, serous, semen & feces)
  • Chemistry (CHEM) – carbohydrates, acid-base, electrolytes, proteins & other nitrogen-containing compounds, enzymes, heme derivatives, lipids & lipoproteins, endocrinology, tumor markers, TDM, toxicology
  • Hematology (HEMA) – erythrocytes & leukocytes, reticulocyte count, ESR, sickle cell test, hemoglobin electrophoresis, RBC enzymes, RBC/WBC morphology & differentials, platelets, hemostasis
  • Immunology (IMMU) – autoimmunity, immune responses, physiology of the immune system, immunology of viral & microbial infectious diseases
  • Microbiology (MICR) – general microbiology, aerobic gram-positive cocci, gram-negative bacilli, gram-negative cocci, gram-positive bacilli, anaerobes, fungus, viruses, mycobacteria, parasites.
  • Laboratory operations (LO) – quality assessment/troubleshooting, safety, management, laboratory mathematics, instrumentation, molecular techniques, education & communication, laboratory information systems

Students with a strong grasp of the aforementioned subjects will likely have the best chances of succeeding on the MLS (ASCP) exam.

Finally, in addition to the suggested reading list and the exam contents overview, ASCP also offers many online practice tests that are available for purchase. While the practice tests will not contain information identical to what will be found on a current exam, completing these sample tests can help an individual simulate test-date conditions.

State Licensure for Medical Laboratory Scientists

As mentioned above, only a certain number of states require individuals to be licensed or certified to work as medical laboratory scientists. Students should visit that state’s medical laboratory personnel licensing board for more information about licensure in any specific state. As an example, Hawaii clinical laboratory specialists must meet one of the following requirements for licensing:

  • Hold a bachelor’s degree from an accredited institution, pass a qualifying exam, and have either one year of work experience or one year of training in an accredited program in the specialty for which the licensure is sought
  • Completed 90 semester hours in an accredited college or university and one year of training in an accredited program in the specialty for which the licensure is sought

This is a thorough yet non-exhaustive list of the eligibility requirements for those interested in pursuing certification as a medical laboratory scientist through ASCP. Like any other career field, someone hoping to work in this profession should perform due diligence and learn as much as possible from all relevant agencies to grasp what to expect throughout each step of the process.

Kimmy Gustafson
Kimmy Gustafson Writer

With her passion for uncovering the latest innovations and trends, Kimmy Gustafson has provided valuable insights and has interviewed experts to provide readers with the latest information in the rapidly evolving field of medical technology since 2019. Kimmy has been a freelance writer for more than a decade, writing hundreds of articles on a wide variety of topics such as startups, nonprofits, healthcare, kiteboarding, the outdoors, and higher education. She is passionate about seeing the world and has traveled to over 27 countries. She holds a bachelor’s degree in journalism from the University of Oregon. When not working she can be found outdoors, parenting, kiteboarding, or cooking.