Iron is the most abundant transition metal element within organisms, and it participates in various physiological activities. Free iron in living cells is particularly important because of its high reactivity, suggesting a relationship to cellular damage or death. Free iron exists in its stable redox states, ferrous ion (Fe2+) and ferric ion (Fe3+). In living cells, research involving this behavior is necessary to understand the intracellular reductive environment, metal transporters and water solubility of Fe2+. FerroOrange is a novel fluorescent probe that enables live-cell fluorescent imaging with fluorescence microscopy and quantitative assay by plate reader. Dojindo has various reagents for ferroptosis research. ( https://www.dojindo.com/ferroptosis-detection-selection-guide/)