What is flow cytometry?

In a world where the fear of disease is ever more paramount, having a way to identify various types of cells that are unique to certain types of conditions is paramount to the continuing health of humans.

In a laboratory, there are many ways to check, identify, count, and detect specific cells, and one of these methods is called flow cytometry. Flow cytometry has been around for many decades, and its clinical use has expanded over the years to provide necessary assistance in the fight against all sorts of diseases and illnesses, especially leukemia.

By using a flow cytometry machine, it is possible to evaluate cells from many different sources, including tumors, blood, cerebrospinal fluid (CFS), bone marrow, and other bodily fluids.

Some examples of tests that use flow cytometry are:

  • Reticulocyte counts – a test to measure how fast red blood cells are released into the blood after being made by the bone marrow.
  • CD4 count – also known as a T-cell count, this test is to measure the number of CD4 cells in your body, white blood cells that fight infection
  • HLA typing – a genetic test particularly useful for people wishing to donate blood or bone marrow
  • Sperm analysis – a test to check the viability and health of sperm, useful for both sperm donors and couples going through IVF treatment
  • Immunophenotyping – a test to determine the level of antigens in the body with relation to certain types of diseases
  • Platelet function tests – an important test to determine the clotting ability of the blood, especially used for issues around bleeding in a clinical setting
  • Bone marrow aspiration and biopsy – often done together, this is the first step in testing bone marrow for all sorts of diseases, especially cancer

By using flow cytometry, it is possible to identify unique cell types that point towards certain diseases. Most commonly, we see flow cytometry used in the diagnoses of blood-related cancers (such as lymphomas or leukemia). The quicker cells are analyzed, the quicker results can be obtained, and getting accurate readings at this stage of investigation may help clinicians to catch issues early, leading to a faster diagnosis, prognosis, and treatment for the patient.

How is flow cytometry carried out?

There are several steps involved in the process of flow cytometry, but above all, great care must be taken. Damage to cells at this stage can slow down both diagnoses and treatment.

To begin with, a small sample of cells is extracted from the patient and suspended in a fluid. It is at this stage that the cells may be treated with special dyes (fluorochromes) to help define cell sub-types, depending on the cells to be analyzed.

The sample passes through the flow cyclometer machine, which organizes cells in a single file ready for analysis. It is at this stage that the utmost care must be taken to ensure the validity of the sample. From here, the machine can determine and identify the characteristics of various cell types, the information on which is analyzed by a computer and displayed as a graph, allowing the clinician to read the results of the test.