Flow Cytometry (Surface Marker Profile)

General Information

Lab Name

Lab Code




The University of Washington Hematopathology laboratory is currently receiving requests for flow cytometry testing that exceed our capacity. We anticipate that turnaround times will be delayed in a subset of MRD flow cytometry cases, and we will no longer be able to regularly provide STAT call backs for MRD flow cases. Additionally, UW Hematopathology is unable to accept flow cytometry reference testing from new clients and will be limiting service to a subset of current clients.

Flow cytometry: This testing may be performed to evaluate antigens expressed by hematopoietic cells. The most common use of flow cytometry is to evaluate for involvement by a hematopoietic neoplasm (for instance leukemia, lymphoma, plasma cell neoplasm, or chronic myeloid neoplasm). Evaluation may include characterization of expression of up to 45 CD markers using antibodies labeled with a fluorescent marker.

If you are unsure if this testing is appropriate, please contact the hemepath fellow on call through the paging operator or contact the laboratory at 206-606-7060.

For information about ordering this service, please contact Client Support Services at 206-520-4600.


CD20 evaluation for Anti-CD20 therapy by flow cytometry, Immunophenotyping, Leukemia or Lymphoma by Flow Cytometry, Rituxan, Rituximab



Flow Cytometry

Interferences and Limitations

The assay is performed by flow cytometric immunophenotyping and interpreted by a trained hematopathologist. The assay has been validated for the diagnosis and monitoring of patients with hematopoietic neoplasms.


Ordering & Collection

Specimen Type

Bone Marrow, BM, Tissue, Cerebrospinal Fluid, CSF, peripheral blood, PB, Body Fluids


LAVENDER TOP (EDTA) or GREEN TOP (Heparin) are acceptable anticoagulants.

Specimen requirements and handling may vary depending on a number of clinical factors; therefore if there are questions or concerns, the laboratory should be consulted prior to obtaining the specimen.

Requirements and Storage


1-6mL LAVENDER TOP (EDTA) or GREEN TOP (HEPARIN) stored at ambient temp

Bone Marrow

First pull collected in LAVENDER TOP (EDTA) or GREEN TOP (HEPARIN) stored at ambient temp

Bone Marrow Biopsy

Submerged in RPMI media stored at 3-5C (REFRIGERATED)


Submerged in RPMI media stored at 3-5C (REFRIGERATED)


Immediately stored 1:1 in RPMI media stored at 3-5C (REFRIGERATED)

Note: If the container is near full, add enough RPMI to still be able to safely store and/or ship.

Body Fluids

Stored at 3-5C (REFRIGERATED)

Rejection Criteria:

· Specimens received in the laboratory >7 days of collection for diagnostic or tissue samples, or >5 days for MRD testing

· Samples received frozen

· Specimen drawn into tubes containing anticoagulant different from specific requirements.

· Specimen drawn into tubes with separator gel, even if not spun

· Clotted (Note: Clotted sample will be disaggregated for testing. Data will be evaluated by Pathologist before sample is rejected.)

· Mislabeled or inadequately-labeled specimens

· Leaking/broken container with no specimen left inside container

· Quantity of sample not sufficient to perform test

· Tissues that have been held in a fixative such as formalin

· Severely hemolyzed specimens

Handling Instructions

· Since flow cytometry is based on evaluation of living cells, specimens should be received within 48 hours of collection for optimal viability. A disclaimer statement regarding limited assay sensitivity due to specimen age may be included in reports for specimens received >72 hours from collection.

· Specimens must be received in the laboratory within 7 days of collection for diagnostic or tissue samples, and 5 days for MRD testing. Specimens received beyond these criteria may be rejected upon receipt.

· The above packaging, transport, and shipping guidelines generally provide acceptable sample quality. However, it is at the discretion of the Pathologist to determine whether the resulting data is unacceptable or non-diagnostic.


requested: Entire sample
minimum: None


SPS, log in as SAVHP and forward to Hematopathology Lab

Storage: BONE MARROW and BLOOD @ Room Temperature. CSF, BODY FLUIDS, and TISSUE in Refrigerator

Note: If specimen arrives after 6:30PM Monday-Sunday forward to Hematopath the following day.

Note2: Hematology/Hematopathology lab will add RPMI media to CSF or fluid specimens on receipt.


LIS Dept Code

Performing Location(s)

Other Hematopathology

UW Hematopathology Laboratory, G7-800
Fred Hutchinson Cancer Center
825 Eastlake Avenue E.
Seattle, WA 98109



Available STAT?


Billing & Coding

CPT codes