Answer:
To make the protein easy to see and identify.
Explanation:
In an experiment to test whether a protein can able to enter the nucleus, the protein should be labeled with a fluorescent molecule. This fluorescent molecule will release fluorescence which can be detected under a fluorescence microscope.
So by attaching the protein with a fluorescent molecule, it will become easy to see the protein and its path because of the fluorescence generated by the attached fluorescent molecule. GFP protein is the most common fluorescent protein used in the imaging of cells.
