ISAC Quality Control and Assurance 3

Question 1

Which statistical tool is most appropriate for comparing flow cytometry results between two instruments to assess method equivalence?

Accepted Answer

Bland-Altman plot

Answer

Bland-Altman plots display the agreement and systematic bias between two measurement methods across the range of values.

Question 2

For a multi-site flow cytometry network, which standardization strategy best ensures inter-site comparability of T-cell subset results?

Accepted Answer

Harmonizing instrument settings using target MFI values derived from common reference beads

Answer

Target MFI-based harmonization using shared reference beads aligns photomultiplier tube voltages across instruments for comparable results.

Question 3

A QC bead lot change results in a shift in the mean channel number on a Levey-Jennings chart. The appropriate corrective action is to:

Accepted Answer

Establish a new baseline mean and SD using the new lot before resuming patient testing

Answer

A new lot requires establishing its own baseline statistics; using old lot parameters would produce false QC failures or false passes.

Question 4

In clinical immunophenotyping, 'gating strategy validation' means:

Accepted Answer

Demonstrating that the gating approach correctly identifies cell populations across a variety of clinical samples

Answer

Gating validation requires demonstrating clinical accuracy and reproducibility across diverse sample types, not just matching a template.

Question 5

Which document provides the primary regulatory framework for quality systems in US clinical laboratories performing flow cytometry?

Accepted Answer

CLIA '88 (42 CFR Part 493)

Answer

CLIA '88 (42 CFR Part 493) establishes federal quality standards for all US clinical laboratory testing including flow cytometry.

(ISAC) International Society for the Advancement of Cytometry Practice Test