

Thymolphthalein (Highly Pure) by Molecular Depot is a thymolphthalein, an acid-base indicator that is colourless below pH 8.5 and blue above pH 9.5. The colour change comes from opening of the lactone ring as the phenolic groups lose their protons. It is used as a pH indicator in alkaline titrations and as the chromogen in alkaline phosphatase assays based on thymolphthalein monophosphate. Each unit contains 1 g. MBP supplies Molecular Depot research reagents to research labs in the United States, Canada and worldwide.