Phen Green SK diacetate is widely used as a fluorescent probe for detecting intracellular metal ions, particularly copper and zinc. Its high sensitivity and selectivity make it a valuable tool in biological and environmental research. In cell biology, it helps visualize and quantify metal ion dynamics within living cells, providing insights into cellular processes and metal homeostasis. It is also employed in environmental studies to monitor metal pollution in water and soil samples. The diacetate form allows for better cell permeability, enabling its use in live-cell imaging and real-time monitoring of metal ion fluctuations.