Litmus is a natural dye extracted from lichens, widely used as a pH indicator in various applications, particularly in laboratories and educational settings. It is commonly employed to determine whether a solution is acidic or basic. Litmus turns red in acidic conditions (below pH 4.8), blue in alkaline conditions (above pH 8.3), and often purple or violet in the transition range around neutral pH. This simple and quick method makes it a valuable tool for preliminary pH testing in chemistry experiments and quality control processes. Additionally, litmus is used in microbiology to assess the acidity or alkalinity of culture media, ensuring optimal growth conditions for microorganisms. Its ease of use and reliability make it a staple in both academic and industrial environments for basic pH analysis.