o-Tolidine is employed as a colorimetric reagent for gold and free chlorine in water. Used in the synthesis of 9,9-bis(3-methyl-4-aminophenyl)fluorine. It is utilized for the detection of reducing sugars by thin layer chromatography. It is used in hair dyes, as a pharmaceutical intermediate and laboratory reagent.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.