SCYM Fluorochrome Selection 2

Question 1

Which fluorochrome has the highest quantum yield among commonly used dyes, making it ideal for detecting low-abundance antigens?

Accepted Answer

R-Phycoerythrin (PE)

Answer

PE has one of the highest quantum yields (~0.98) of commonly used fluorochromes, making it excellent for detecting low-abundance antigens.

Question 2

When designing a multicolor panel, a marker with very high expression should be paired with a fluorochrome that has:

Accepted Answer

Low brightness

Answer

Highly expressed antigens should be paired with dim fluorochromes to prevent spillover from oversaturation overwhelming adjacent detector channels.

Question 3

Which property of a fluorochrome directly determines the amount of spectral spillover into adjacent channels?

Accepted Answer

Emission spectrum width and tail

Answer

The width and tail of the emission spectrum determine how much signal from one fluorochrome bleeds into adjacent detector channels.

Question 4

BV421 is best excited by which laser line commonly found on flow cytometers?

Accepted Answer

405 nm violet laser

Answer

BV421 (Brilliant Violet 421) is optimally excited by the 405 nm violet laser and emits around 421 nm.

Question 5

Which fluorochrome is most susceptible to photobleaching during extended acquisition times?

Accepted Answer

FITC

Answer

FITC is highly susceptible to photobleaching compared to more photostable alternatives like BV dyes or tandem conjugates.

(SCYM) Specialist in Cytometry Practice Test