Question 1

Forward scatter is related to what cellular feature?&#10;A)density&#10;B)size&#10;C)granularity&#10;D)complexity

Accepted Answer

Information gathered from the detector situated directly in line with the illuminating source is called forward scatter and provides data on particle size.

Question 2

Hydrodynamic focusing in flow cytometry is important because it&#10;A)directs the laser light.&#10;B)intensifies the laser light with mirrors.&#10;C)collects the scattered light.&#10;D)creates a core of individually aligned cells.

Accepted Answer

Hydrodynamic focusing creates a central stream of individually aligned cells surrounded by sheath fluid.This is essential for consistent illumination of each cell as it passes in front of the gas laser light source.

Question 3

What is an early marker of erythroid precursors?&#10;A)CD45&#10;B)CD71&#10;C)CD34&#10;D)CD8

Accepted Answer

CD71 identifies the presence of the transferrin receptor and is found on early erythroid precursors.

Question 4

All of the following are true concerning hematopoietic stem cells except&#10;A)they express both CD34 and CD117 (c-kit).&#10;B)they lose some antigens as they mature.&#10;C)they express both CD4 and CD34.&#10;D)they gain lineage-specific antigens as they mature.

Accepted Answer

CD4 is a marker of T cells,not hematopoietic stem cells (HSCs).HSCs express both CD34 and CD117 (c-kit).As they mature,some antigens are lost while lineage-specific antigens are gained.

Question 5

What cell type expresses CD20 and contains immunoglobulin light chains on the surface but not in the cytoplasm?&#10;A)helper T cells (TH)&#10;B)T suppressor cells&#10;C)immature B cells&#10;D)mature B cells

Accepted Answer

Mature B cells express CD20 and immunoglobulin light chains,either k or l but not both,on their surface.

Question 6

What marker is most closely related to disease progression in acquired immune deficiency syndrome (AIDS)patients?&#10;A)CD3&#10;B)CD4&#10;C)CD8&#10;D)CD10

Accepted Answer

Progression of human immunodeficiency virus (HIV)infection into AIDS is accompanied by a decrease in the number of CD4-positive cells (T_H).

Question 7

Myeloid stem cells and blasts express which of the following on their surface?&#10;A)CD4&#10;B)CD8&#10;C)CD34&#10;D)terminal deoxynucleotidyl transferase (TdT)

Accepted Answer

CD34 is expressed on the surface of myeloid stem cells and blasts.CD4,CD8,and TdT are all markers of lymphoid lineage.In addition,TdT is not a membrane antigen but rather is found in the nucleus.

Question 8

The presence of TdT is characteristic of progenitors of which lineage?&#10;A)megakaryocytes and platelets&#10;B)monocytes&#10;C)erythrocytes&#10;D)lymphocytes

Accepted Answer

TdT is found in lymphoid precursors and is useful for identifying their presence.

Question 9

Staining a sample with deoxyribonucleic acid (DNA)dyes such as propidium iodide is done to determine cell&#10;A)viability.&#10;B)ploidy.&#10;C)lineage.&#10;D)chromosome number.

Accepted Answer

Flow cytometry must be performed on viable cells;thus assessment of cell viability is routinely determined before analysis.Propidium iodide is a dye that stains DNA and permits this evaluation.

Question 10

A patient has a white cell count of 12.6 * 10⁹/L,hematocrit of 28%,and platelet count of 27 * 10⁹/L.Examination of a Wright-stained blood film reveals that almost all of the white cells in peripheral blood are blasts;the bone marrow is hypercellular with very little fat and is packed with blasts.Flow cytometry is performed on the peripheral blood cells,and a large cluster of cells is present that mark with CD20 and have monoclonal k light chains present on their surface.This patient has

A)myeloid leukemia.
B)a mature B-cell malignancy.
C)a reactive B-cell hyperplasia.
D)a mature T-cell malignancy.

Accepted Answer

Mature B lymphocytes express CD20 and either k or l light chains on their surface.In a B-cell reactive process,a mixture of k and l light chain positivity will be observed.The expression of only one light chain on the surface of a population of B cells is called monoclonality and is indicative of a phenotypically mature B-cell malignancy.

Question 11

Which of the following is evaluated using fluorochrome dyes that are bound to monoclonal antibodies?&#10;A)membrane antigens&#10;B)nuclear complexity&#10;C)number of lymphocytes&#10;D)cell size

Accepted Answer

The answer of Which of the following is evaluated using...

Question 12

Which of the following is true regarding the relationship between flow cytometry and the microscopic evaluation of leukemic cells?&#10;A)Flow cytometry has made microscopic analysis outmoded.&#10;B)Methods are best used together to establish a diagnosis.&#10;C)More cells can be analyzed by looking under the microscope.&#10;D)The human eye is more sensitive than flow cytometry and better at finding weak antigenic expression.

Accepted Answer

The answer of Which of the following is true regarding...

Deck 32: Flow Cytometric Analysis in Hematologic Disorders