The green fluorescent protein (GFP) is a protein composed of 238 amino acid residues (26.9kDa) that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range. In cell and molecular biology, the GFP gene is frequently used as a reporter of expression.EGFP fluorescence is stable under fixation conditions and suitable for a variety of applications. EGFP has been widely used as a reporter for gene expression, enabling researchers to visualize and localize EGFP-tagged proteins within living cells without the need for chemical staining.