Used as a pH indicator in microbiology and analytical chemistry, particularly in the methyl red test to identify bacteria that perform mixed acid fermentation, such as Enterobacteriaceae. It helps differentiate microbial species based on their ability to produce stable acids from glucose metabolism. The indicator changes color from red (acidic) to yellow (basic) with a sharp transition around pH 4.4 to 6.2. Also employed in titrations, pH measurement in laboratory settings, quality control in the food and beverage industry, and wastewater analysis in water treatment processes.