O-NITROPHENYL-ß-D-GALACTOPYRANOSIDE (oNPG) Grade:ULTRA PURE GRADE CAS Number: 369-07-3Synonym(s): 2-Nitrophenyl β-D-galactopyranoside, ONPG Molecular Weight: 301.25Molecular Formula: C12H15O8N Storage Condition: FROZEN CodeSizePriceQuantity 0789-5G 0789-25G Chromogenic substrate for the detection of beta-Galactosidase. Commonly used in ELISA. Read at 410 nm. Soluble. Reaction Condition: 7 mg/ml in PBS, 1 mM MgCl2, 10 mM BME, pH 7.5. Stop reaction with 2 M Sodium Carbonate.