m-Cresol purple indicator by Research Lab Fine Chem Industries is a high grade reagent. Also known as Metacresol purple, this is a triarylmethane dye. The reagent is available as a powder which is insoluble in water. While it is stable under general conditions, this reagent is incompatible with strong oxidizing agents. CAS No.: 2303-01-7 Quantity Provided: 1 gm per bottle Molecular formula: C21H18O5S Molecular weight: 382.44 Assay: 90 %m-Cresol purple has a variety of applications in chemical and biological sectors. This reagent finds applications in the organic synthesis of various derivatives. m-cresol purple acts as a pH indicator where at pH 1.2 - 2.8, it turns from red to yellow and at 7.4 - 9.0 it turns from yellow to violet. This compound also plays an important role in spectrophotometric pH measurements. m-Cresol purple is utilized to stain epithelial cells and proteins. This reagent is suitable for industrial synthesis of products and research applications.