Methyl red solution is widely used as a pH indicator in analytical chemistry and microbiology. It is particularly effective in titrations involving strong acids and weak bases, where it provides a clear color change from red (acidic, pH below 4.4) to yellow (basic, pH above 6.2). This sharp transition makes it valuable for determining the endpoint in acid-base titrations. In microbiology, methyl red is used in the methyl red test, a key test in identifying certain bacteria, especially in the differentiation of Enterobacteriaceae. For example, it helps distinguish Escherichia coli (which gives a positive result, turning red) from Enterobacter aerogenes (which gives a negative result, remaining yellow). This application is crucial in clinical labs for bacterial identification and diagnostic procedures. It is also used in educational laboratories for teaching acid-base chemistry due to its reliable and visible color change. Methyl red solution is typically prepared in ethanol or water and is favored for its stability and ease of use in routine testing.