Question

Which of the following is not a fluorescence dye?

• A. Alexa Fluor
• B. Green fluorescent protein (GFP)
• C. Red fluorescent protein (DsRed)
• D. Xylene cyanol

Hint:

Understand the difference between fluorescent dyes and tracking dyes in molecular biology applications.

Answer 1

The Correct Option is D

Xylene cyanol is a tracking dye used in gel electrophoresis to visualize DNA or RNA migration. Unlike Alexa Fluor, GFP, and DsRed, which emit fluorescence and are widely used in imaging studies, Xylene cyanol does not have fluorescent properties.