What should you know about FACS flow cytometry?

FACS means fluorescence-activated cell sorting. In the laboratory, cells from blood, bone marrow, lymph nodes or another sample pass one by one through a laser beam. Antibodies carrying fluorescent labels bind to selected cell markers. Detectors record patterns such as marker presence, cell size and internal complexity. The instrument can then place cells with a chosen pattern into separate collection tubes.

The result helps specialists describe cell populations and may support the assessment or classification of blood and immune-system disorders. It is interpreted alongside symptoms, examination findings and other laboratory or tissue results.

FACS is usually performed on a sample collected by a healthcare professional rather than by placing you in a machine. Ask whether your sample is blood, bone marrow or tissue and whether any preparation is needed. If a bone marrow sample is planned, ask how the site will be numbed, how long soreness may last and how results will be communicated. Do not assume the technical label alone predicts the diagnosis.

After a blood draw, seek advice for bleeding that does not stop with pressure, increasing swelling or signs of infection. After a bone marrow procedure, contact the care team for worsening pain, persistent bleeding, fever, spreading redness or drainage. Seek urgent care for fainting that does not settle, severe breathing difficulty or sudden severe illness.

Ask which cell markers are being assessed, what sample was tested, whether sorting is needed, which other results will be combined with flow cytometry, and when the findings will guide the next decision.