What should you know about multicolour flow cytometry?

A sample of blood, bone marrow, or another body fluid is prepared in the laboratory. Antibodies attach to selected markers on or inside cells. As cells pass through the instrument, lasers excite the attached fluorescent labels. The machine records several signals from each cell, allowing specialists to assess a group of markers together rather than relying on one feature alone.

The result can help distinguish immune-cell populations, recognise immature or unusual cells, and classify some blood and bone-marrow disorders. It is interpreted alongside symptoms, examination findings, blood counts, microscopy, genetics, and other tests. A flow result is not, by itself, a complete diagnosis or a measure of how a person will respond to treatment.

Ask which sample is needed and whether any preparation is required. Blood collection usually involves a routine sample, while a bone-marrow sample is collected by a separate procedure. Tell the team about medicines, bleeding problems, allergies, or previous difficulty with blood tests.

After collection, follow the laboratory or clinic instructions. Results may take time because the laboratory must select the relevant cell populations and interpret a complex marker pattern. Request an explanation of what was tested, which cells were found, and whether another sample or test is needed.

Contact the clinical team promptly if the sampling site keeps bleeding, becomes increasingly red or swollen, or develops worsening pain or discharge. After a bone-marrow procedure, seek urgent advice for heavy bleeding, fever, severe pain, fainting, or new weakness. These symptoms need assessment because they can signal a complication of sampling or another medical problem.

Which sample was tested, and what cell populations were measured? What does the marker pattern show about the cells? Could the result be affected by the sample quality or recent treatment? When will the report be reviewed, and which further tests could clarify it?