What does the term "tagged protein" refer to in GFP experiments?

The term "tagged protein" in the context of GFP experiments specifically refers to a protein that has been fused or labeled with GFP. This process allows researchers to visualize the protein of interest within a cellular environment using fluorescence microscopy. The GFP acts as a tag that emits green fluorescence when exposed to ultraviolet or blue light, making it easier to track the localization and dynamics of the target protein in live cells.

By attaching GFP to another protein, scientists can monitor its expression and interactions in real-time without altering its natural behavior significantly. This technique is widely used in molecular and cell biology research to study the function and distribution of proteins in various biological processes.