Medical laboratory professionals are part of your health care team. We work behind the scenes, but what we do has a direct impact on patient care. Medical laboratory professionals process and analyze samples to provide information vital to patients’ health. We are behind every lab test result, and our work provides answers to guide diagnosis, treatment and patient care.

Medical Laboratory Professionals

There are different roles and specializations within the profession. Medical laboratory professionals are trained to have the right knowledge and skills to perform duties specific to their roles.

Here are the four specialized roles of medical laboratory professionals.

Hover your cursor over each image below to learn more about each profession.



Medical laboratory technologists, or MLTs, analyze samples, such as tissues and body fluids, to provide results for physician diagnosis and treatment. MLTs specialize in several areas:

  • Clinical chemistry, the testing of blood and body fluids to detect chemicals, hormones, or drugs
  • Clinical microbiology, the testing of blood, body fluid and other samples to detect bacteria, fungi, viruses and parasites
  • Hematology, the testing of blood to detect blood diseases and disorders
  • Transfusion science, the testing of blood to determine type and compatibility
  • Histology, the preparing of samples of body tissue to detect disease


Diagnostic Cytology Technologists are health professionals that analyze cellular changes that can determine the presence of specific diseases. Mostly through the use of slides under a microscope, diagnostic cytology technologists are able to detect pre-cancerous cells. An abnormal finding would be sent to a pathologist for a final diagnosis.



Clinical Genetics Technologists use a variety of instruments to analyze and diagnose changes or abnormalities in chromosomes and DNA, which are unique to every individual. A genetics technologist's analysis of these cells can lead to a diagnosis of genetic diseases.



Medical Laboratory Assistants (MLAs) work under the supervision of a Medical Laboratory Technologist (MLT), performing the practical components of sample analysis. MLAs sort, prepare and sometimes process samples that will be tested and analyzed by an MLT. MLAs often collect samples, such as blood, and are often the laboratory professionals that interact directly with patients.

Meet the Professionals

Since many of us work in the medical laboratory, we don’t get to meet patients very often. But we think it’s time you got to know us! Meet a few of us below. You might be surprised about the wide range of the things we do.

Ivan Aditya
Kamloops, BC

  • Diagnostic Cytology MLT
  • Cytotechnology Technical Lead at Royal Inland Hospital Lab, Interior Health
  • 7 years as a CSMLS member

I am proud to be a 2018 American Society for Clinical Pathology 40 Under 40 honoree.

Paula Van Vliet
Regina, SK

  • General MLT specializing in Transfusion Science
  • Transfusion Safety Manager at Regina General Hospital
  • 36 years as a CSMLS member

Figuring out a complex antibody is comparable to a good murder mystery. Transfusion Medicine Technologists are the Nancy Drews of the lab.

Hansika Deepak
Toronto, ON

  • MLA
  • Medical Laboratory Technician at University Health Network
  • 7 years as a CSMLS member

My philosophy when providing patient care is "heal with a smile and the treatment goes miles."

Roy Chen
Vancouver, BC

  • General MLT specializing in Clinical Microbiology, Clinical Chemistry, Hematology, Transfusion Science, Histology
  • Laboratory Research Coordinator at Provincial Health Services Authority
  • 9 years as a CSMLS member

I am an enthusiastic MLT always looking to meet professionals from various clinical specialties. As a research coordinator in the laboratory, it allows me to do just that.

Maria Roussakis
Mississauga, ON

  • General MLT specializing in Clinical Chemistry, Hematology, Transfusion Science
  • Medical Laboratory Technologist at William Osler Health System
  • 5 years as a CSMLS member

I am fortunate to have the skills and knowledge needed to help doctors diagnose diseases, as well as make a positive impact on the health of the patient.

Brendan O'Brien
St. John's, NL

  • Diagnostic Cytology MLT
  • Cytotechnologist III at Eastern Health
  • 5 years as a CSMLS member

When I'm not behind my microscope I also co-teach a health research course at Dalhousie University, hike the many trails of Newfoundland with my greyhound, and train and compete in CrossFit with my friends.

Judy Tran
Toronto, ON

  • General MLT specializing in Hematology
  • Medical Laboratory Technologist at University Health Network
  • 4 years as a CSMLS member

I have taught medical laboratory techniques and experiments in science outreach programs to high school students from around the world.

Rania Elhalabi
Moncton, NB

  • General MLT specializing in Hematology
  • Coagulation Supervisor at Moncton Hospital
  • 17 years as a CSMLS member

I am passionate about the profession. I've volunteered locally, provincially and nationally, and I am involved in many initiatives at my workplace.

Hélène Lanigan
Sainte-Thérèse-de-la-Gatineau, QC

  • General MLT specializing in Clinical Chemistry, Clinical Microbiology, Hematology, Histology
  • Regional Quality Manager for CISSS laboratories in the Outaouais region
  • 24 years as a CSMLS member

I am the Quality Manager for seven labs in the Outaouais region. I am always working to make sure every patient recieves the care they deserve.

A Day in the Life

Being a medical laboratory professional isn’t easy. We never know what the day holds. One moment we could have to put everything aside to run a stat test — an urgent test someone’s life might depend on. In another moment, we could be called back to the lab — in the middle of the night, in a storm. Any moment of the day, life as a medical laboratory professional is demanding. But we love what we do because we know we make a difference in the lives of others.

Now that you know what we do, take a look at how we do it. Meet the medical laboratory professionals below to experience life in the lab.

In the Lab

Your host Andrew Chapman illustrates the importance of the medical laboratory profession by giving you an inside look at the inner workings of a busy laboratory in both a hospital and private lab. We’ll go behind the laboratory doors at Toronto General Hospital at UHN and LifeLabs to speak with medical laboratory professionals who complete the health care picture.


Complete Blood Count (CBC) Test


Protein Electrophoresis Test


Cross Matching Test




Mass Spectrometry



The Lab and You

Medical laboratory professionals work to provide critical information that helps guide medical decisions about your health. They sort, prepare and analyze samples from virtually every part of your body - from head to toe.

Discover how medical laboratory professionals are involved in your health. Click on the points to learn about some of the testing done on that body part.


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Sample taken from a skin biopsy

This is a Histotechnological stain applied on skin tissue which includes a hair follicle. The actual name of this stain is Hematoxylin and Eosin (better known as H&E). It is a routine stain applied to tissues received in the Histopathology lab. ALL tissues removed from patients (surgical, biopsy, autopsy) are sent to the Histopathology lab.

Once received in the lab, medical laboratory professionals put the samples through a series of processes, including staining. After applying stains, the tissue components will pick up the dye in the staining solution making them visible under the microscope. The medical laboratory professional ensures the samples are processed correctly before handing them to a pathologist for a diagnosis. This is the only way the tissues from the patient can be diagnosed; through the visualization of the tissue architecture by the pathologist.

H&E Stained
Not Stained

courtesy of The Michener Institute Histology Faculty


Red Blood Cells

Sample taken from a vein

Blood can tell many stories. Blood tests are often ordered through a routine health exam or when there are symptoms that require further investigation.

A medical laboratory professional will view the prepared blood sample under a microscope. How the blood cells appear is important information used in diagnosis.

Anemic Blood
Normal Blood

Credit: Sysmex Corporation


Bacterial Infections

Sample taken from the throat

Bacteria grow in your body causing an infection, making you feel ill or in pain. A very common bacterial infection is strep throat, caused by a group A streptococcal infection.

Your doctor or nurse will take a throat swab to get a sample of the bacteria cells in your throat. Then the sample is sent to the lab to grow the bacteria to determine the type, in order to know the treatment.

A medical laboratory professional will take a very small part of the sample and touch it to a petri dish that has been treated to enable bacteria growth. They will then use a small, sterile instrument to spread the cells around the dish, this is called streaking. It helps to separate as many cells as possible.

Once the bacteria begins to grow it may look like this in the petri dish.

courtesy of

The medical laboratory professional will then take a small part of the growing bacteria and process it, including staining (or adding colour) in order to view the cells under a microscope. This helps determine what strain or type of bacteria is present and which antibiotic will treat it.



Sample taken from a liver biopsy

Depending on the results of blood work and ultrasounds, a primary physician may recommend a liver biopsy. This might be for patients with a history of alcohol abuse or those who have had a hepatitis infection at one point.  They will likely have their liver function monitored by a specialist on a regular basis so that cirrhosis will not ensue or progress further.

In this sample we see adipose tissue (fat) infiltrating the normal architecture of the liver specimen, seen as the large white cells. The presence of fat amongst the normal liver architecture is a tell-tale sign that you are visualizing a progressed disease. A fatty liver can be the result of several diseases or disorders including alcohol abuse, obesity and hepatitis.

H & E Stained
Not Stained

courtesy of The Michener Institute Histology Faculty

A medical laboratory professional would process the biopsy sample in order for a pathologist to make a visual diagnosis. You can see the importance of staining a sample, in order to see the various structures.


Heart Attack

Diagnosed through blood tests

The signs of a heart attack can look different for different people; one of the most accurate ways to know if a heart attack has occurred is through a blood test.

A blood sample is taken and sent to the lab where it is prepared for chemical analysis. A medical laboratory professional will separate the sample to run several tests. Using an analyser, they are looking for specific biomarkers that will determine if the patient is experiencing a heart attack or not.

Biomarkers are released into the blood when there is damage to muscle cells, in this case the heart muscle. They include:

  • Troponin – testing for this protein is done several times over a time period to monitor the increase or decrease of levels. The results over the series of tests will indicate a heart attack. 
  • CK-MB – an enzyme found in the heart muscle which will increase when there is damage.


Sample taken from a bone biopsy

Osteoblasts are one of the cell types that form bone. They are seen here in a bone biopsy. A biopsy might be performed to check for infection, cancer or other bone diseases. This image is of normal bone that has been decalcified (removal of the hard calcium), processed and stained (coloured) by laboratory professionals and magnified under a microscope. It will be given to a pathologist for examine and possible diagnosis.


Human Papilloma Virus

Sample taken from a pap smear

This image shows squamous epithelial cells infected with Human Papilloma Virus (HPV). These cells are from a Pap test (Papanicolaou test). This routine test involves taking a sample from a woman's cervix to screen for cervical cancer. The sample is processed, stained (coloured) and examined by laboratory professionals.


Urinary Tract Infection

Sample taken from a urine sample

Bacteria are everywhere! These single cell organisms live and grow in our bodies at all times. The majority of bacteria are healthy and assist in keeping our bodies functioning correctly. These include bacteria in our digestive systems and on our skin that help protect our immune system. Sometimes bacteria are harmful and can cause infections and diseases.

The laboratory can take a sample of the bacteria in question and  grow it in the ideal conditions to see what forms. Once grown, the bacteria is categorized and a diagnosis can be made and appropriate treatment can begin.

courtesy of 2nd year students at The Michener Institute: EJ Lazaga and Stephen Yee

In this short video we can see the bacteria growing in an incubated chromomogenic media over 18 hours. The larger pink colonies are Escherichia coli (E. coli) and the smaller blue colonies are Enterococcus faecalis. Both organisms are common in urinary tract infections and can be a life threatening highly antibacterial resistant strain.


Pleural Fluid

Sample taken from pleural space

Pleural fluid is found in the membranes surrounding your lungs. It's normal to have a small amount of this fluid as it helps us breathe normally. With certain diseases such as lung cancer, too much fluid is produced. This is a picture of pleural fluid from someone with metastatic lung cancer. The large purple cell in the middle is a cancerous cell. Laboratory professionals prepare, stain and examine this type of fluid and identify the cells found in it. If a cell looks suspicious it is referred to a pathologist for final diagnosis.


Renal Tubules

Sample taken from a kidney biopsy

Renal tubules are the small tubes found in your kidneys that contain fluid filtered by the kidneys. As fluid travels through these tubules it is further filtered. Anything your body requires such as water, electrolytes, glucose and amino acids are kept and anything that is not needed is excreted as urine. This image is of a normal renal tubule has been processed and stained (coloured) by laboratory professionals and magnified under a microscope. A renal tubule may appear abnormal in diseases such as systemic lupus erythematosus or with kidney failure.


Tissue Biopsy

Sample taken from a biopsy

Sometimes diagnosing the cause of illness can require several tests. The combination of results from x-ray, ultrasound and blood testing might only provide part of the story. Your doctor may need a closer look at what's happening under the skin surface and that will lead to a tissue biopsy.

A sample of tissue is removed from the body (biopsy) and is prepared for visual analysis under the microscope by a pathologist. A medical laboratory professional in the histology lab, performs several steps to ensure the sample is prepared correctly for the most accurate results.

Step 1: The tissue is processed to dehydrate it and then embedded into a wax mold.

Step 2: The wax-embedded tissue is sliced very finely to reveal deeper layers

Step 3: The thin layers of wax-embedded tissue is mounted on a microscope slide and stained to enhance details

Step 4: The slide is viewed under the microscope where normal and abnormal cells can be viewed.



Analysis of urine is a very common lab test as it can provide a host of information.

Your sample is sent to the lab in the sterile specimen cup, where a medical laboratory professional will do a visual analysis before preparing it for further testing. They then dip a specialized strip of paper into the urine to start the chemical analysis.


The strip is placed into an analyzer that will give a read out of chemical levels. These levels might indicate some of the following:

  • Blood
  • White blood cells and other signs of infection
  • Sugars
  • pH levels (acidity)

If there are abnormal readings, the sample is spun in a centrifuge to separate the fluid from the sediment. A drop of the sediment is viewed under the microscope where a medical laboratory professional could see:

  • Red and/or white blood cells
  • Epithelial (skin) cells
  • Bacteria or yeast
  • Parasites
  • Crystals

The results from all the testing are recorded and given to your health care provider.


Did You Know?

Hundreds of millions of lab tests are performed every year in Canada. Medical laboratory professionals run these tests to provide critical information about your health. Get a deeper look at how these tests are performed, why they are done and how medical laboratory professionals get results.

Cancer -


New cases of cancer diagnosed in Canada in 2019

Leukemia -


Canadians will be
diagnosed with leukemia

Papanicolaou Test - Diagnostic Cytology


Pap tests are done every year
in Canada

Prenatal Screening - Clinical Genetics


Canadian women undergo amniocentesis each year

Blood Donation - Transfusion Science


every 60 seconds, someone in Canada needs blood

Genetic Testing Surge - Clinical Genetics


genetic testing products on the market today

Clinical Chemistry

Vitamin D Tests

The demand for laboratory tests is always increasing. The volume of some tests have risen exponentially. In the case of vitamin D tests, the number of tests ordered have increased dramatically, driven by the interest of both doctors and their patients in the purported health benefits of the vitamin.

The number ordered by doctors rose to about 700,000 in 2009 from 29,000 in 2004.1

Read More


Sexually Transmitted Infections

Laboratory tests are required for an accurate diagnosis of the specific bacteria causing a sexually transmitted infection (STI). This information is vital to providing effective treatment, as each bacteria would respond to a different antibiotic.

In 2010, there were:

94,690 reported cases of chlamydia, 11,397 reported cases of gonorrhea, and 1,757 reported cases of infectious syphilis.2

Read More



Medical laboratory technologists play a vital role in the diagnosis process. The testing done in the laboratory is key to assisting in early detection and treatment.

Read More

Transfusion Science

Blood Donations

Every 60 seconds, someone in Canada needs blood.

Blood and blood products are a critical part of everyday medical care including major surgeries, medical procedures, cancer treatments and managing disease.

Medical laboratory assistants often draw blood from patients for clinical or medical testing, transfusions, donations, or research.

Medical laboratory technologists, specifically those in transfusion science, conduct blood typing and blood compatibility tests. This is vital for any blood donation and subsequent transfusions.

Read More

Clinical Genetics

Prenatal Screening

10,000 Canadian women undergo amniocentesis each year.

Amniocentesis (also referred to as amniotic fluid test or AFT) is a test in which fetal DNA is examined for genetic abnormalities.

Laboratory professionals called Genetic Technologists analyze and diagnose abnormalities in chromosomes and DNA, which are unique to every individual. Their analysis can lead to a diagnosis of genetic diseases.

Read More

Clinical Genetics

Genetic Testing Surge

There are more than 75,000 genetic testing products on the market today.

Genetic testing has evolved in complexity beyond the single-gene paradigm, the genetic testing market has become similarly complex and dynamic.

These new and abundant genetic tests would be performed by Genetic Technologists, who diagnose abnormalities in chromosomes and DNA which can lead to diagnosing genetic diseases.

Read More


Clinical Chemistry


Almost every hour, more than 20 people are newly diagnosed with diabetes. Each diagnosis is made through a laboratory blood test called Hemoglobin A1c.

A medical laboratory professional processes a blood sample to determine the level of glucose (sugar) that is present in the blood. They can tell this by the level of glycated hemoglobin (or A1c) that is present, because A1c is present when glucose attaches to hemoglobin.

Once a diagnosis is made, diabetes can be monitored and managed with the help of continual laboratory tests.8

Read More



In 2019, an estimated 6,700 Canadians were diagnosed with leukemia.

Leukemia is a cancer that starts in blood stem cells. Stem cells are basic cells that develop into different types of cells that have different jobs.

Medical laboratory technologists conduct a complete blood count (CBC) on your blood sample, which measures the number and quality of white blood cells, red blood cells and platelets. Leukemia and other conditions can cause abnormal blood cell counts.

Read More

Diagnostic Cytology

Papanicolaou Test

Over 4,000,000 Pap tests are done every year in Canada.

Pap test samples are processed, stained (coloured) and examined by laboratory professionals called cytotechnologists. This method of cervical screening is used to detect potentially pre-cancerous and cancerous cells.

Read More

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