ISAC Panel Design and Fluorochrome Selection

Question 1

What is the primary consideration when selecting fluorochromes for a multicolor flow cytometry panel?

Accepted Answer

Spectral overlap between fluorochromes

Answer

Cost of the reagents

Answer

Color preference of the researcher

Answer

Availability of secondary antibodies

Question 2

In panel design, a bright fluorochrome like PE should ideally be assigned to which type of marker?

Accepted Answer

Dimly expressed or rare markers

Answer

Highly expressed surface markers

Answer

Markers used only as lineage dump

Answer

Markers with bimodal expression only

Question 3

What is spectral spillover in flow cytometry?

Accepted Answer

Detection of one fluorochrome's emission in another fluorochrome's detection channel

Answer

Loss of signal caused by laser power fluctuations

Answer

Cross-contamination of samples in the flow cell

Answer

Autofluorescence signal produced by unlabeled cells

Question 4

Which parameter is most important for evaluating fluorochrome brightness in the context of panel design?

Accepted Answer

Staining index

Answer

Molecular weight of the fluorochrome

Answer

Excitation wavelength alone

Answer

The visible color of the fluorochrome solution

Question 5

What is a tandem dye in flow cytometry?

Accepted Answer

A fluorochrome consisting of two energy-coupled dyes that shift emission to a longer wavelength

Answer

Two separate antibodies used simultaneously against the same antigen

Answer

A dual-laser instrument configuration

Answer

A detection filter paired with a dichroic mirror

Question 6

Why is minimizing spectral overlap between fluorochromes a key goal in panel design?

Accepted Answer

It reduces compensation requirements and preserves signal resolution

Answer

It reduces the cost of reagents per experiment

Answer

It simplifies gating hierarchies in the analysis software

Answer

It allows the use of fewer antibody clones

Question 7

Which laser is most commonly used to excite FITC and propidium iodide (PI) in flow cytometry?

Accepted Answer

Blue laser (488 nm)

Answer

Red laser (633 nm)

Answer

Violet laser (405 nm)

Answer

Yellow-green laser (561 nm)