Assays Performed by Flow Cytometry

Flow Cytometry


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 allows rapid identification and quantification of subpopulations of cells in suspension through assessment of physical properties and antigen expression. Suitable specimens include fresh blood, bone marrow, body fluids, or tissue samples. (See specimen handling requirements.) Samples are incubated with flourescently-tagged antibodies directed against specific cell surface proteins. The antibodies used are generally tailored to specimen type, clinical history and suspected diagnosis. Our current clinical instruments are capable of simultaneously examining up to 10 different antigens, providing a very high level of sensitivity and allowing identification of abnormal populations at diagnosis as well as the identification of small abnormal populations in the post-therapy setting (minimal residual disease testing).

Hematopoietic disorders

Leukemia/Lymphoma Panel

Hematopathologic Diagnostic Pathway

  • Reflexive testing pathways provide comprehensive and cost-effective evaluation for hematopoietic disorders. Hematopathologic Diagnostic Pathway [EVALHD] (only available within UW Medicine and FHCC patients) typically includes flow cytometry and often includes morphology, cytogenetic and molecular studies. The Pathways, Evaluate for Hematopoeitic Disorder test order is an algorithm of diagnostic tests to be performed based on the clinical indications. It attempts to streamline testing, minimize unnecessary testing and maximize optimal use of limited sample materials, and was developed in conjunction with our clinicians here at UW/FHCC.

Paroxysmal Nocturnal Hemoglobinuria (PNH)

PNH by Flow Cytometry [PNHFLO]


The UW Hematopathology Laboratory is currently being impacted by a global supply shortage of a critical component of our Lymphocyte Subset Enumeration assays. Until reagent is made available by the manufacturer, lymphocyte subset enumeration assays listed below will be sent to a referral laboratory for testing as early as Friday, September 23. To ensure sample viability for testing, please schedule collections so that samples are received in our lab on weekdays and no later than noon on Fridays. Samples received later than noon on Friday or over the weekend will have an increased risk for cancellation due to limited stability.

The following tests are affected:

· Lymphocyte subsets, T and B cell counts [TCSP]

· Lymphocyte subsets, T, B, NK cell counts [TCSNK]

· CD19+ B Cell Count [BCS19]

Lymphocyte Enumeration (BAL or CSF)

Lymphocyte Subset Enumeration (Blood Only)

Cell sorting for chimerism

For questions regarding Flow Cytometry services: Ph: 206-606-7060 Fax: 206-606-7127.


  • Chen X, et al. Relation of clinical response and minimal residual disease and their prognostic impact on outcome in acute myeloid leukemia. J Clin Oncol 2015, 33:1258-64. 25732155
  • Walter RB, et al. Comparison of minimal residual disease as outcome predictor for AML patients in first complete remission undergoing myeloablative or nonmyeloablative allogeneic hematopoietic cell transplantation. Leukemia 2015, 29:137-44. 24888275
  • Zhou Y, et al. Pre- and post-transplant quantification of measurable ('minimal') residual disease via multiparameter flow cytometry in adult acute myeloid leukemia. Leukemia 2016, 30:1456-64. 27012865
  • Walter RB, et al. Significance of minimal residual disease before myeloablative allogeneic hematopoietic cell transplantation for AML in first and second complete remission. Blood 2013, 122:1813-21. 23847197
  • Walter RB, et al. Impact of pretransplantation minimal residual disease, as detected by multiparametric flow cytometry, on outcome of myeloablative hematopoietic cell transplantation for acute myeloid leukemia. J Clin Oncol 2011, 29:1190-7. 21282535
  • Loeb KR, et al. Comparative analysis of flow cytometry and morphology for the detection of acute myeloid leukaemia cells in cerebrospinal fluid. Br J Haematol 2016, 172:134-6. 26010105
  • Seegmiller AC, et al. Optimizing personalized bone marrow testing using an evidence-based, interdisciplinary team approach. Am J Clin Pathol 2013, 140:643-50. 24124142

Associated Tests

Code Name Specimen
BALTCS T Cell Subsets, BAL BAL, Bronchoalveolar Lavage
EVALHD Hematopathologic Diagnostic Pathway Peripheral Blood (PB), Bone Marrow...
FLOW Flow Cytometry Panel Order Bone Marrow, BM, Tissue,...
PNHFLO PNH by Flow Cytometry Peripheral Blood
SMP Flow Cytometry (Surface Marker Profile) Bone Marrow, BM, Tissue,...
TCS48 T cell subsets CD4/CD8 only, counts Blood
TCSA T cell subsets CD3/CD4/CD8, counts Blood
TCSNK Lymphocyte subsets, T, B, NK cell counts Blood
TCSP Lymphocyte subsets, T and B cell counts Blood