Deck 13: Flow Cytometry and Laboratory Automation

Question 1

What are the advantages of automated testing in a clinical immunology laboratory?

A) Requires minimal investment and maintenance
B) Reduces turnaround time
C) Increases hands-on time by staff
D) Does not require validation

Answer 1

Reduces turnaround time

Question 2

A fluorescent signal in flow cytometry is generated by:

A) light reflected off cells passing through a laser beam.
B) light scattered by fluorochromes.
C) fluorochromes that absorb energy from a laser beam and then release the energy as longer-wavelength light.
D) cell metabolism.

Answer 2

fluorochromes that absorb energy from a laser beam and then release the energy as longer-wavelength light.

Question 3

An intrinsic parameter that can be measured by a flow cytometer is:

A) surface expression of CD3.
B) granularity.
C) cytoplasmic protein content.
D) RNA content.

Answer 3

granularity.

Question 4

A mature cytotoxic T cell expresses which markers?

A) CD3, CD4, and CD8
B) CD4, CD3, and CD5
C) CD5, CD8, and CD3
D) CD8, CD3, and CD2

Question 5

Fluorescently labeled antibodies are used in flow cytometry to determine:

A) the size of a cell.
B) the granularity of a cell.
C) proteins associated with a cell.
D) the shape of the nucleus.

Question 6

Which light signal in flow cytometry provides information about a cell's intrinsic physical characteristics?

A) Green light emitted by fluorescein isothiocyanate (FITC)
B) Red light emitted by phycoerythrin
C) Polarized light
D) Scattered light

Question 7

The expression of cell surface markers is determined in the flow cytometer by which of the following?

A) Chemiluminescence
B) Fluorescence
C) Optical density
D) Radioactivity
E) Scatter

Question 8

A test system is producing many false-positive results.You suspect this is a problem involving:

A) analytic specificity.
B) precision.
C) analytic sensitivity.
D) a sampling error.

Question 9

In flow cytometry,if there are two light detectors,what does the amount of side scatter indicate?

A) Size of the cell
B) Granularity of the cell
C) Surface markers
D) Shape of the cell

Question 10

Hydrodynamic focusing in flow cytometry refers to the:

A) diameter of the laser beam.
B) refractive properties of the assay buffer.
C) orientation of the photomultiplier tubes.
D) alignment of the cells flowing past the laser beam.

Question 11

What is meant by "gating" in flow cytometry?

A) The chromatic arrangement of cellular populations
B) The process by which one cell population adheres to another population
C) An electronic window separating subpopulations of cells
D) An electronic device measuring all populations of cells

Question 12

Which description best describes the reportable range?

A) Span of test result values over which the laboratory can establish or verify the accuracy of an instrument or test system
B) Range of test values found in a healthy population of people
C) Variation observed in repeated measurements of the same sample
D) Difference in concentration between the highest and lowest standards used in the standard curve

Question 13

The reference interval is determined by:

A) using a standardized reagent to establish the highest and lowest concentrations that can be measured by an instrument or test system.
B) measuring an analyte in samples from a large number of healthy people, using the same instrument or test system.
C) the period of time between the acquisition and testing of a sample.
D) the difference in concentration between the highest and lowest standards used in the standard curve.

Question 14

Identify the difference between batch and random-access analyzers.

A) Batch analyzers are not automated.
B) Random-access analyzers only analyze one sample at a time.
C) Batch analyzers only do one type of analysis at a time.
D) Random-access analyzers cannot be used for stat samples.

Question 15

In flow cytometry,the sheath fluid:

A) contains a dye required for cell identification.
B) draws the suspended cells into a laminar flow.
C) filters out extraneous wavelengths of light.
D) provides nutrients necessary to maintain cellular metabolism.

Question 16

What is a disadvantage of automated testing in a clinical immunology laboratory?

A) Decreases potential for manual errors
B) Increases dependence on a single machine
C) Cannot be used within the preanalytical stage of testing
D) Cannot perform combined chemistry and immunoassay testing on a single platform

Question 17

In most flow cytometers,labeled cells:

A) scatter the light and absorb fluorescence.
B) absorb fluorescence and emit electronic impulses.
C) scatter the light and emit fluorescence.
D) absorb both fluorescence and light.

Question 18

Which light signal in flow cytometry could be used to provide information about the expression of a protein on the outer surface of a cell membrane?

A) Forward-angle light scatter
B) Red light emitted by phycoerythrin
C) Polarized light
D) Right-angle light scatter

Question 19

As measured in flow cytometry,cells that are the smallest and have the least granules would be identified as:

A) lymphocytes.
B) granulocytes.
C) monocytes.
D) erythrocytes.

Question 20

The lowest measurable amount of an analyte is called:

A) accuracy.
B) precision.
C) analytic sensitivity.
D) analytic specificity.

Question 21

In flow cytometry,forward scatter provides a measure of:

A) cell size.
B) cell granularity.
C) membrane receptor expression.

Question 22

A single cell parameter acquired by flow cytometry is presented graphically as a:

A) histogram.
B) dot plot.
C) vector plot.
D) quadrant analysis.

Question 23

In flow cytometry,it is possible to detect the expression of 10 different cell membrane proteins simultaneously by:

A) using 10 different lasers that produce light at different wavelengths.
B) measuring the amount of light scattered at 10 different angles.
C) staining the cells with 10 different labeled probes that fluoresce at different wavelengths.
D) measuring mass as well as fluorescent intensity.

Question 24

Flow cytometry is commonly used to:

A) measure serum protein concentrations.
B) identify microbes.
C) determine the stage of leukocyte differentiation.
D) measure complement activation.

Question 25

How close a measured value is to the actual (true)value is called:

A) accuracy.
B) precision.
C) analytic sensitivity.
D) analytic specificity.

Question 26

The ability to consistently reproduce the same result on repeated testing of the same sample is called:

A) accuracy.
B) precision.
C) analytic sensitivity.
D) analytic specificity.

Question 27

In flow cytometry,fluorescence is usually used to determine:

A) intrinsic cell parameters.
B) extrinsic cell parameters.