Flow Cytometry and Laboratory Automation

Flow cytometry characterizes cells on the basis of which of the following?

• a. Forward and 90-degree side scatter of an interrupted beam of light
• b. Front-angle scatter only of an interrupted light beam
• c. Absorbance of light by different types of cells
• d. Transmittance of light by cells in solution

Forward-angle light scatter is an indicator of cell

• a. granularity.
• b. density.
• c. size.
• d. number.

What is the single most important requirement for samples to be analyzed on a flow cytometer?

• a. Whole blood is collected into a serum-separator tube.
• b. Cells must be in a single-cell suspension.
• c. Samples must be fixed in formaldehyde before processing.
• d. Blood must be kept refrigerated while processing.

Which statement represents the best explanation for a flow cytometer's ability to detect several cell surface markers at the same time?

• a. The forward scatter can separate out cells on the basis of complexity.
• b. One detector can be used to detect many different wavelengths.
• c. For each marker, a specific fluorochrome-antibody combination is used.
• d. Intrinsic parameters are separated out on the basis of the amount of side scatter.

Which of the following cell surface markers would be present on a population of T helper (Th) cells?

• a. CD3 and CD4
• b. CD3 and CD8
• c. CD3 only
• d. CD4 only

If an analyzer consistently indicates a positive test when the analyte in question is not present, this represents a problem with

• a. sensitivity.
• b. specificity.
• c. reportable range.
• d. precision.

All of the following are clinical applications for flow cytometry except

• a. fetal hemoglobin.
• b. immunophenotyping of lymphocyte subpopulations.
• c. HIV viral load analysis.
• d. enumeration of stem cells in a peripheral blood mononuclear cell product.

The various signals generated by cells intersecting with a flow cytometry laser are captured by

• a. bandwidth waves.
• b. wave channels.
• c. photomultiplier tubes.
• d. flow cells.

Analysis of flow cytometer data of cells can be filtered in many ways by using a method of

• a. "gating" in a dot plot.
• b. banding of a histogram.
• c. single-parameter histogram monitoring.
• d. automatic sampling.

A newer flow cytometry technology that has the potential to detect over 500 analytes from one sample of blood is called a/an

• a. RBC fragmentation assay.
• b. Dihydrorhodamine 123.
• c. sucrose test.
• d. cytometric bead array.