2-Nitrophenyl ß-D-galactopyranoside, =98% (enzymatic)

Synonym: o-Nitrophenyl ß-D-galactopyranoside, ONPG

CAS Number: 369-07-3

Empirical Formula (Hill Notation): C₁₂H₁₅NO₈

Molecular Weight: 301.25

Beilstein Registry Number: 92207

EC Number: 206-716-1

MDL Number: MFCD00063055

PubChem Substance ID: 24897461

General Description
ONPG (2-Nitrophenyl ß-D-galactopyranoside) is a colorimetric substrate for ß-galactosidase.

Packaging
1 g in poly tube; 250 mg in poly bottle;, 5, 25 g in poly bottle; 500 mg in poly tube

Principle
ß-galactosidase, breaks down lactose into galactose and glucose.
ß-Galactosidase is not lactose specific and can act on simple galactosides.
2-Nitrophenyl ß-D-galactopyranoside hydrolysis results in the release of galactose and a yellow chromogenic compound. The test substrate does not depend on an induced or constitutive permease enzyme to enter the cell, therefore reactions are rapid and occur within a 24-hour period.

Reconstitution
A stock solution can be prepared in molecular biology grade water at a concentration of 3 mg/ml. Alternatively, a stock solution of approximately 20.5 mg/ml is prepared in 100 mM sodium phosphate buffer (pH 7.3). Gentle warming may be required to completely dissolve the product.