CAS Registry Number

CAS 2303-01-7 — m-Cresol Purple

m-Cresol Purple is a synthetic pH indicator dye used primarily in biochemical assays, urine tests, and buffer solutions to detect pH changes between 1.2 and 2.8, transitioning from yellow to purple. It is also employed in clinical diagnostics for protein detection in urine. This chemical has a CAS number of 2303-01-7, a molecular formula of C₂₁H₁₈O₅S, and a molecular weight of 382.42962 g/mol. It is stable at ambient storage conditions and carries no signal word for hazard classification. Molekula supplies m-Cresol Purple from research to bulk quantities with full documentation and ISO 9001:2015 traceability.