What is flow cytometry?
Flow cytometry is a laboratory technique that can be used for counting, examining, and sorting cells. The technology to perform flow cytometry is often incorporated into automated laboratory equipment such as hematology (blood) analyzers.
In flow cytometry, the sample is passed through a light source, typically a laser. As the cells in the sample move through the light's path, they scatter the light. The pattern of scattering is a function of both the size of the cell and its internal complexity. The scattered light is captured by lenses and translated into an electrical signal, which is further analyzed by a computer and displayed as a graphical representation of the cell populations in the sample.
What types of samples can be analyzed by flow cytometry?
Anything that can be suspended in a liquid (thereby allowing a smooth flow of material through the flow chamber) can be analyzed. In veterinary medicine, the most common samples analyzed are peripheral blood samples (blood that travels through the heart, arteries, veins, and capillaries), and cells derived from body cavity fluids or tissues (lymph nodes, bone marrow).
What are the uses of flow cytometry in veterinary medicine?
Flow cytometry is incorporated into automated hematology analyzers to count and group cells within a blood sample. Another use for flow cytometry is the characterization of cellular subpopulations. For example, it may be difficult to distinguish benign from malignant (cancerous) lymphocytes (a type of white blood cell) within a blood or tissue sample based on microscopic cellular features alone. Using flow cytometry and antibodies to specific proteins on the lymphocyte cell membrane, the lymphocytes present in a sample can be broken down into subpopulations. The presence of many different subpopulations of lymphocytes is more consistent with a benign inflammatory or reactive process, whereas the presence of a uniform population is supportive of a malignant lymphocyte population.
Can flow cytometry be done in general veterinary practice?
No, typically the equipment needed to perform this technique, and the expertise required to interpret the findings, are only available in university or referral settings. However, many such centers accept samples from veterinary clinics for analysis.
