Medical Laboratory Scientist Practice Test

If you need help studying for the Medical Laboratory Scientist (MLS) exam or just want some more information about what the exam is like, you’ve come to the right place.

Click below to take a free AMT MLS practice test!

Exam Eligibility

Before you can register to take the Medical Laboratory Scientist exam, you’ll need to make sure you meet the necessary eligibility requirements of at least one of the three routes:

Route 1: Education
To follow this route, you’ll need a bachelor’s degree in medical laboratory science from an accredited institution recognized by a regional or national accreditation agency, earned within the last five years.

Your education should include a minimum of one year of clinical laboratory experience, covering areas like blood banking, chemistry, hematology, and microbiology.

Route 2: MLT/Military
This route requires a bachelor’s degree in medical laboratory science from an accredited institution or an equivalent foreign degree approved by the American Medical Technologists (AMT).

Additionally, you must have completed an accredited MLT program or a 50-week US MLT training program, along with at least one year of approved clinical laboratory experience.

Route 3: Alternate Education
For this route, a bachelor’s degree in medical laboratory science from an accredited institution or an equivalent foreign degree approved by AMT is necessary. You must have completed 35 semester hours in relevant clinical laboratory service coursework, including organic chemistry, biochemistry, biological science, microbiology, and mathematics.

Additionally, you must have either completed an accredited medical technology training program or have at least one year of approved clinical laboratory experience within the last five years.

What’s on the Exam?

Questions: 210
Time limit: 3.5 hours

There are 210 multiple-choice questions on the AMT MLS exam, and the time limit is 3.5 hours.

Let’s take a closer look at the different sections of the MLS exam.

30 questions

  • General microscopy
  • Instrumentation, maintenance, and principles of operation
  • Laboratory quality
  • Laws and regulations
  • Mathematics
  • Patient identification
  • Phlebotomy and specimen collection
  • Safety
  • Waived testing

45 questions

  • Acid-base balance
  • Carbohydrate metabolism
  • Cerebrospinal fluid
  • Endocrinology
  • Enzymology
  • General knowledge
  • Hepatic function tests
  • Instrumentation
  • Lipids
  • Other chemistry procedures
  • Protein analysis
  • Renal function tests
  • Water and electrolytes

32 questions

  • Automated instrumentation
  • Erythrocyte procedures
  • General knowledge
  • Leukocyte procedures
  • Special procedures
  • Thrombocyte procedures

15 questions

  • Factor testing
  • Fibrin degradation products
  • Fibrin split products
  • General knowledge
  • Heparin assay
  • Partial thromboplastin time
  • Platelet function tests
  • Prothrombin time

8 questions

  • Analytical procedures
  • General knowledge
  • Serological tests for syphilis
  • Special procedures

22 questions

  • Blood typing
  • Compatibility testing principles and procedures
  • General knowledge
  • Immune response
  • Rh immune globulin
  • Special tests

17 questions

  • Blood donor requirements
  • Blood storage requirements
  • Evaluation of blood donor collection requirements and deferrals
  • General knowledge
  • Labeling requirements
  • Quarantine procedures
  • Regulation parameters for computer crossmatch
  • Regulations for the disposition of blood bags
  • Therapeutic phlebotomy

31 questions

  • Bacterial identification
  • General knowledge
  • Media quality control, techniques, and cultures
  • Mycology
  • Parasitology
  • Special tests
  • Virology

10 questions

  • General knowledge
  • Renal function
  • Special tests
  • Urinalysis procedures

How to Register

To get started with the registration process, you’ll need to submit an application via the AMT website. Your application will need to include the $245 application fee.

Once your application is approved, you’ll be sent information on how to set up your testing appointment, which can be held at a testing center or online.

MLS Study Guide and Flashcards

Get practice questions, detailed study lessons, and complex subjects broken down into easily understandable concepts.

Study Guide

Exam Scores

The Medical Laboratory Scientist exam is scored using a scaled scoring method. Here’s how it works:

For every question you answer correctly, you get one point added to your raw score. At the end of the test, your final raw score will be converted to a scaled score. This scaled score will range somewhere between 0 and 100. You will need a score of at least 70 to pass the test.

The reason your raw score is converted to a scaled score is because everyone who takes the test is given a slightly different set of questions. Since everyone has a different arrangement of questions, and because some questions are harder than others, converting your raw score to a scaled score ensures a more even playing field.

Retaking the Exam

If you didn’t get a passing score on your first try, that’s okay! You can take the exam again up to three more times.



How many questions are on the MLS exam?


The exam contains 210 multiple-choice questions.


What is the time limit for the MLS exam?


The exam is timed at 3.5 hours.


What is the passing score for the MLS exam?


To pass the exam, you’ll need a minimum scaled score of 70.


How much is the MLS exam?


The application fee is $245.