Used as a redox indicator in biochemical assays, particularly in electron transport studies. Commonly applied in microbial fuel cells and enzymatic reactions to monitor electron transfer. Also utilized in histology for staining nucleic acids in cells, allowing visualization of nuclei and chromosomes under light microscopy. Its ability to penetrate cell membranes makes it effective for live-cell imaging and metabolic studies. Frequently employed in educational labs to demonstrate redox processes due to its clear color change between oxidized and reduced states.