Question 1

A mature cytotoxic T cell expresses which markers?&#10;A) CD3,CD4,and CD8&#10;B) CD4,CD3,and CD5&#10;C) CD5,CD8,and CD3&#10;D) CD8,CD3,and CD2

Accepted Answer

Mature cytotoxic T cells express CD8, CD3, and CD2 markers. CD8 is the co-receptor for MHC class I molecules, CD3 is part of the T-cell receptor complex, and CD2 is involved in adhesion and activation of T cells.

Question 2

In most flow cytometers,labeled cells:&#10;A) scatter the light and absorb fluorescence&#10;B) absorb fluorescence and emit electronic impulses&#10;C) scatter the light and emit fluorescence&#10;D) absorb both fluorescence and light

Accepted Answer

In flow cytometry, a laser beam is used to illuminate labeled cells as they pass through a fluidic system. Labeled cells scatter the incident light in different directions and emit fluorescence in response to the excitation. Therefore, the correct option is that labeled cells scatter the light and emit fluorescence.

Question 3

What is meant by &#34;gating&#34; in flow cytometry?&#10;A) the chromatic arrangement of cellular populations&#10;B) process by which one cell population adheres to another population&#10;C) an electronic window separating subpopulations of cells&#10;D) an electronic device measuring all populations of cells

Accepted Answer

Gating in flow cytometry refers to the process of separating or isolating specific cell populations based on a set of parameters or characteristics. This is typically done electronically using a gating tool that creates a window or gate around the cells of interest, separating them from the rest of the sample. Therefore, option C is the correct answer. Options A, B, and D do not accurately describe gating in flow cytometry.

Question 4

Which is a difference between batch and random access analyzers?&#10;A) Batch analyzers are not automated.&#10;B) Random access analyzers only analyze one sample at a time.&#10;C) Batch analyzers only do one type of analysis at a time.&#10;D) Random access analyzers cannot be used for stat samples.

Accepted Answer

Batch analyzers typically perform one type of analysis on multiple samples simultaneously, whereas random access analyzers can perform multiple types of analyses on different samples in a non-sequential manner.

Question 5

As measured in flow cytometry,cells that are the smallest and have the least granules would be identified as:&#10;A) lymphocytes&#10;B) granulocytes&#10;C) monocytes&#10;D) erythrocytes

Accepted Answer

Lymphocytes are the smallest cells and have the least granules. Granulocytes, on the other hand, are larger and have distinct granules visible under the microscope. Monocytes are larger than lymphocytes and have minimal granules that are not visible with routine staining. Erythrocytes do not have a nucleus and are not measured with flow cytometry.

Question 6

Which of the following is an intrinsic parameter that can be measured by a flow cytometer?&#10;A) surface expression of CD3&#10;B) internal complexity&#10;C) fluorescence intensity&#10;D) nuclear morphology

Accepted Answer

Internal complexity is an intrinsic parameter measured by flow cytometry, often assessed by side scatter, which indicates the granularity or complexity within a cell.

Question 7

In flow cytometry,if there are two light detectors,what does the amount of side scatter indicate?&#10;A) size of the cell&#10;B) granularity of the cell&#10;C) surface markers&#10;D) shape of the cell

Accepted Answer

Side scatter measures the granularity or complexity of the cell. The more side scatter, the larger and more complex the cell. It is not related to cell size, surface markers, or cell shape.

Question 8

If a test system has many false-positive results,this is a problem involving:&#10;A) accuracy&#10;B) precision&#10;C) analytic sensitivity&#10;D) sampling error

Accepted Answer

False-positive results indicate that the test is not accurately detecting the intended target or condition, leading to inaccurate results. Therefore, this problem involves accuracy.

Question 9

The expression of cell surface markers is determined in the flow cytometer by which of the following?&#10;A) chemiluminescence&#10;B) fluorescence&#10;C) optical density&#10;D) radioactivity&#10;E) scatter

Accepted Answer

Flow cytometry analyzes cells by detecting fluorescently-labeled surface markers using laser excitation.

Question 10

A range of values that all produce a positive result is known as:&#10;A) analytic sensitivity&#10;B) reportable range&#10;C) accuracy&#10;D) precision

Accepted Answer

The reportable range is the range of values that can be measured by a laboratory assay and produce results that are accurate and precise enough to be reported. A reportable range must have a lower limit of detection (the lowest concentration that can be reliably detected) and an upper limit of linearity (the highest concentration where the assay remains accurate and precise). Therefore, a range of values that all produce a positive result would fall within the reportable range.

Deck 12: Flow Cytometry and Laboratory Automation