What is a common application of purified GFP in research?

Purified Green Fluorescent Protein (GFP) is widely used in research primarily for studying gene expression and protein interactions. This application arises from the unique properties of GFP, which emits a bright green fluorescence when exposed to ultraviolet or blue light. By tagging proteins or genes of interest with GFP, researchers can visually track the location and abundance of these proteins within living cells or tissues.

This ability allows scientists to understand how genes are expressed in different conditions and to investigate interactions between proteins in real-time, providing insights into cellular processes and pathways. For example, researchers can create fusion proteins that include GFP, allowing them to observe the behaviors and interactions of those proteins in a biological context. This method of visualization is invaluable in fields such as molecular biology, cell biology, and developmental biology, where understanding the dynamics of proteins in live cells is essential for elucidating complex biological functions.

In comparison, while other applications of GFP listed might have their own research significance, they do not leverage the same capabilities of GFP in terms of real-time visualization of cellular processes and protein behavior, making the study of gene expression and protein interactions the most prominent and impactful use of purified GFP.