Resazurin is widely used as an indicator in various biological and chemical applications. In microbiology, it is employed to assess cell viability and microbial growth, where its color change from blue to pink or colorless indicates metabolic activity. It is also utilized in redox assays to measure cellular respiration and electron transport chain activity. In the food industry, resazurin serves as a marker for milk quality, detecting bacterial contamination. Additionally, it is used in environmental monitoring to evaluate water quality and the presence of microorganisms. Its applications extend to drug screening, where it helps determine the efficacy of antimicrobial agents by measuring cell survival rates.