SCYM Quality Control & Assurance 3

Question 1

In cytometry, 'carryover' contamination between samples is best minimized by:

Accepted Answer

Running a wash or rinse cycle between samples

Answer

Wash or rinse cycles flush residual cells from the fluidics pathway, preventing carry-over to the next sample.

Question 2

What defines the linear dynamic range of a flow cytometer detector?

Accepted Answer

The range of signal intensities over which detector response is proportional to fluorescence input

Answer

Linear dynamic range is the span of intensities where the detector produces a proportional, accurate output without saturation.

Question 3

A lab processes QC samples at the beginning and end of each analytical run. This practice is designed to detect:

Accepted Answer

Instrument drift occurring during the run

Answer

Bracketing runs with QC samples reveals drift in instrument performance across the analytical session.

Question 4

Which action should be taken when a QC result fails the Westgard 1-3s warning rule?

Accepted Answer

Investigate potential causes and perform additional QC testing before releasing patient results

Answer

The 1-3s exceedance is a warning signal; laboratory protocol requires investigation and confirmatory QC before patient results are released.

Question 5

Light scatter QC on a flow cytometer typically uses which type of reference material?

Accepted Answer

Polystyrene microspheres of defined size

Answer

Polystyrene microspheres have defined, stable size and refractive index, making them ideal for light scatter alignment and QC.

(SCYM) Specialist in Cytometry Practice Test