Introduction to Flow Cytometry: Blood Cell Identification Exam

CD5 antigen is normally found on which of the following lymphocyte populations?

mature t cells Feedback CD5 is present on mature T cells, but is not present on normal B cells. The presence of CD5 on B cells may indlcate a B cell malignant process

Which of the following represents the percent population of T-helper cells in this sample data? Absolute lymphocyte count= 2.4 x 109/L %CD3 = 60%CD4 = 40%CD8 = 20

40% feedback T-helper cells are CD4 positive. The flow results reflected 40% CD4.CD3 is a pan T cell marker (and should reflect CD4 plus CD8).CD8 is the cytotoxic T cell marker.

Which of the following CD markers is NOT present on a normal mature T cell?

CD20 Feedback CD20 is not present on mature T cells. CD20 is expressed by B cells.Normal mature T cells should express CD2, CD3, CD5 and CD7

During the flow cytometry analysis process, cells exiting the flow cell intersect a laser, and produce what kind of data?

Intrinsic cell characteristics Extrinsic cell characteristics Forward scatter Fluorescence feedback As cells exit the flow cell in single file, they intersect the laser and emit the following data: Intrinsic cell characteristics Size (forward scatter) Granularity (side scatter) Extrinsic cell characteristics Surface Antigens (fluorescence emitted by the MoAb bound to the specific antigens)

Select each marker listed below that is expressed by a normal mature B cell.

CD19 CD20 Kappa or Lambda

A monoclonal B-cell population (Kappa or Lambda predominant) with expression of CD19, CD20, CD23, and co-expression of CD5 is consistent with which of the following?

Chronic lymphocytic leukemia Feedback If Kappa or Lambda is predominant and CD5 is co-expressed with CD19 (CD19/CD5 dual positive lymphocyte population), and CD23 is expressed, chronic lymphocytic leukemia is a probable diagnosis. CD19 is normally found on normal B cell populations and CD5 is normally found on mature T cell populations. However, CD5 is present on B cells in B-chronic lymphocytic leukemia or Mantle Cell Lymphoma, both abnormal B cell malignant processes.

Monoclonal antibodies are designed to bind to all antigens on cell surfaces.

Feedback The statement is false. Monoclonal antibodies are designed to bind only to specific matching antigens. This principle is what allows for sorting of individual cell lines and populations within a sample containing a mix of different types of cells. Leukemias and lymphomas can be diagnosed and staged using monoclonal antibodies that are specific to their correlating antigens.

Extrinsic cell characteristics are reflected by the forward and side scatter on a flow cytometry cytogram.

false feedback Feedback The statement is false. Intrinsic cell characteristics (size and granularity) are represented by forward and side scatter. Extrinsic cell characteristics are represented by the fluorescent signal produced as a result of tagged monoclonal antibodies binding to antigens on the cell surface.

When analyzing the raw data of a sample on the flow cytometer, CD marker information on the histograms represents data inside the _____ population.

gated feeback Feedback Gating sets up boundaries around a subset of data points to segregate those events for analysis.Gating the proper cell population is crucial for flow cytometric analysis. The CD marker information presented on the histogram data is only representative of the cells inside the gate.

During the 'staining' process prior to flow cytometry analysis of white blood cells, erythrocytes are _______ .

lysed feeback Erythrocytes are lysed prior to flow cytometry analysis of white blood cells. Unless red blood cells are the population of interest, they should be lysed with a mild agent that will preserve the integrity of the cells targeted for analysis. If the red blood cells are not lysed, they lead to false analytic results.

cd2 is expressed by

mature t cells