Flow cytometry in the clinical setting is most commonly used for the evaluation of leukemia and lymphoma. Cells of lymphoid and hematopoietic origin express various surface markers which can be tagged with fluorescent dye bound antibodies. These antibody bound cells can be passed single
file through the cytometer flow cell, excited by a laser, and individually enumerated. The data generated from analysis by flow cytometry may be evaluated in combination with cell morphology and other studies and is integral to arriving at a differential diagnosis which may serve as the basis for determining treatment selection.
Specimen: Peripheral Blood
At least 3 mL of peripheral blood in EDTA/purple top or sodium heparin/green top. Lithium Heparin is not suitable for flow cytometry. Refrigerate/transport with ice pack. Do not freeze.
Specimen: Bone Marrow
At least 2 mL of aspirate in EDTA/purple top or sodium heparin/green top. If no aspirate is obtained (dry tap), core biopsy may be submitted in RPMI (in addition to the core biopsy submitted in formalin for histologic evaluation).
Specimen: Fine Needle Aspiration Biopsy
Specimen should be collected in RPMI. Several passes should be made, rinsing the needle thoroughly in RPMI after each pass. (Use clean, sterile needle for each pass). Transport to lab immediately at 2-4°C (refrigerated). Specimens fixed in Cytolyt or other cytology fixative are unsuitable for flow cytometry.
Fresh tissue (preferably 1cm2) should be placed directly in RPMI. Transport immediately to lab at 2-4°C (refrigerated). Specimens fixed in formalin are unsuitable for flow cytometry. Please submit a separate specimen for routine histologic examination.
*If less than 2 cm2 of tissue is available for histologic examination and flow cytometry combined, please contact the laboratory for assistance.