Used as a solvent in the preparation of p-dimethylaminobenzaldehyde test solution for detecting indoles, such as in microbiological assays and clinical diagnostics. It ensures proper solubilization of p-dimethylaminobenzaldehyde, enabling the reagent to react with indole compounds to form a visible colored complex. Commonly applied in biochemical tests, including the identification of bacteria like Escherichia coli in laboratory settings.