Flow Cytometry


Flow Cytometry




Flow cytometry measures physical and chemical properties of the cells. The cells pass the flow cytometric analyzer in a fluid, single-cell stream. The laser beams interrogate each cell and indicate the cell size, internal complexity and the antigens present on cell surface or in the cytoplasm.


  1. Each specimen is manually processed.
  2. A smear (peripheral blood or bone marrow aspirate) or touch prep (tissue) slide is made from the original specimen.
  3. A cytospin slide is made from the final cell suspension.
  4. The slides are prepared and evaluated by a hematopathologist.
  5. Every specimen for flow cytometric analysis is manually processed.
  6. Panels of surface/intracellular markers are chosen to stain the cells based on morphology and clinical history.
  7. After the cells are stained, they are acquired and analyzed with the flow cytometer.
  8. The immunophenotyping panel configurations are carefully considered based on stateof-the-art scientific references, consensus, and the experiences of hematopathologists.
  9. The combinations of antibodies allow for the identification of normal and abnormal populations of cells within a specimen.
  10. Antibody panels cover acute leukemia, chronic leukemia, T and B cell lymphoma, multiple myeloma,neoplasms and others.


Complete a <Bone Marrow Biopsy Information> requisition.  Indicate specimen type; number and type of tubes; number of smear or touch prep slides submitted.  It is important to indicate the diagnosis under consideration and the indication for flow cytometry testing.

The following information must be completed on each requisition.

  1. Patient’s Name
  2. Patient’s Date of Birth
  3. Social Security Number (if available)
  4. Date and time of collection
  5. Specimen source or type (i.e. Bone marrow, left cervical lymph node, etc.)
  6. Requesting Physician name and contact phone number
  7. Thorough clinical history
  8. Indicate whether Flow Cytometry is needed.
  9. All insurance information must be included to ensure proper billing.


Bone Marrow Aspirate/ Peripheral Blood Smears, Bone Marrow, Peripheral Blood, Solid Tissue (FNA), Body Fluids (CSF).


  1. All specimen types, regardless of method of collection, must be legibly labeled with the patient’s name (last name and first name initial are acceptable) matching with that on the requisition form.
  2. Minimally, the last name must be legible and correctly spelled.
  3. Second identifier such as date of birth, chart number, SSN# or other unique identifier is required.
  4. The specimen type and collection site (i.e. peripheral blood, bone marrow; right iliac crest, etc.) must be indicated.


Bone Marrow:

  • 2-7 mL bone marrow aspirate collected in Sodium Heparin (green top) tube; Purple top (EDTA) tube acceptable; Yellow top (ACD) tube only if no other options.
  • Deliver to lab immediately (within 12-hours) and transport at room temperature
  • (20—25° C). DO NOT REFRIGERATE.

Peripheral Blood:

  • 3-5 mL collected in NaHep (green top) tube.
  • 3-5 mL collected in EDTA (purple top) tube for morphology.
  • Deliver within 24-hours of collection.
  • Transport at room temperature (20-25°C).
  • Include CBC results if performed.

Solid Tissue/ FNA:

  • 5 mm solid tissue specimen cut aseptically into small pieces and placed in RPMI media and stored at (2-8°C).
  • FNA specimen placed in RPMI media and stored at (2-8°C).
  • Transport on “wet” ice. DO NOT SEND ON DRY ICE AND DO NOT FREEZE.

Body Fluids:

  • Volume required for testing depends on the cell count of the specimen.
  • Specimen handling varies depending on the specimen type.
  • CSF requires processing within one hour of collection for optimal results.


Occasionally a physician may submit a specimen for possible flow cytometry, depending on the results of permanent sections expected at a later time. The specimen will be held for 2-3 days, during which time the physician must contact the laboratory to request flow analysis.

A specimen may also be received with a diagnosis that does not warrant flow cytometry testing (Hodgkin lymphoma, carcinoma, certain body fluids, etc.). These specimens are held until reviewed by the pathologist assigned to the case. The paperwork is placed in the file cabinet. The specimen is kept for one week and then discarded.


A specimen may be rejected if it is frozen or fixed, too old, or if it is hemolyzed or clotted.

All specimens MUST be labeled with at least the patient’s name and date of collection. Other identifying information is useful, such as hospital number.