SCYM Fluorochrome Selection 5

Question 1

When selecting fluorochromes for a clinical diagnostic panel, which regulatory consideration is most critical?

Accepted Answer

Selecting FDA-cleared reagents validated for the intended clinical application

Answer

Clinical panels must use FDA-cleared or validated reagents to ensure diagnostic accuracy, reproducibility, and regulatory compliance.

Question 2

Fluorochrome-conjugated antibodies stored incorrectly in light can degrade due to which phenomenon?

Accepted Answer

Oxidative quenching from ambient light exposure (photobleaching)

Answer

Exposure to ambient light causes photobleaching of fluorochromes, reducing conjugate brightness and increasing lot-to-lot variability.

Question 3

Which of the following is the correct approach when a required marker has very low density on the cell surface (dim antigen)?

Accepted Answer

Pair it with the brightest available fluorochrome to maximize signal

Answer

Dim antigens must be paired with the brightest fluorochromes available to ensure the signal rises above background noise.

Question 4

What is the main reason BV dyes (Brilliant Violet) should not be used with certain detergent-based permeabilization buffers?

Accepted Answer

Detergents can cause BV dye aggregation, increasing background fluorescence

Answer

Certain detergent-based permeabilization buffers cause BV polymer dyes to aggregate, producing high nonspecific background and altered spectral profiles.

Question 5

Which approach allows the detection of two proteins expressed at similar levels using fluorochromes with overlapping spectra?

Accepted Answer

Selecting fluorochromes on different laser lines to eliminate co-excitation

Answer

Placing spectrally similar fluorochromes on different laser lines avoids co-excitation and enables independent signal detection for both markers.

(SCYM) Specialist in Cytometry Practice Test

(SCYM) Specialist in Cytometry Practice Test

SCYM Fluorochrome Selection 5