Used as a pH indicator in laboratory settings, particularly in microbiology and analytical chemistry. It helps detect changes in acidity, turning red in acidic conditions (pH below 4.4) and yellow in neutral or slightly basic conditions (pH above 6.2). Commonly applied in bacterial culture tests, such as the methyl red test, to identify organisms that produce stable acids from glucose fermentation, like Escherichia coli. Also used in titrations and environmental testing to monitor pH shifts in solutions.