Used as a redox indicator in titrations, Methylene Blue indicator solution changes color from blue to colorless when reduced, making it ideal for detecting the endpoint in redox reactions. Commonly applied in analytical chemistry for the determination of reducing agents. Also utilized in biological staining to highlight cells or tissues under microscopy, particularly in microbiology and histology. In environmental testing, it helps assess the oxygen demand in water samples. Additionally, it serves in educational labs to demonstrate electron transfer processes and redox behavior in a visible manner.