Green fluorescent protein (GFP) is genetically fused to many proteins in various species to generate non-reactive chimeras which are known to preserve their original biological activity as well as the fluorescent properties of native GFP. GFP acts as a reporter for gene expression and as a fusion tag for protein localization studies in live cells. It serves as a spectroscopic and microscopic probe to understand the biological functions of various systems. GFP is highly stable and can serve as a tool for in vitro studies.
