Endocytosis contributes to the maintenance of intracellular homeostasis by bringing in various nutrients to the cell and transporting unwanted components to the lysosome, acting as a waste disposal system. Fluorescent dextran conjugates, internalized via endocytosis, are widely used for monitoring the endocytic pathway in living cells. However, dextran size affects both internalization and dynamics inside the endocytic pathway, suggesting that care must be taken when using dextran conjugates. ECGreen is a small molecule fluorescent probe that is not membrane permeable. ECGreen is internalized via endocytosis and its fluorescence intensity is enhanced as the acidity increases. Unlike conventional dextran conjugates, ECGreen allows direct observation of the membrane of an internalized vesicle, making it suitable for live-cell imaging of endocytosis. Dojindo offers various reagents for cell membrane research. (https://www.dojindo.com/track-the-dynamics-of-plasma-membrane/)