Skip to Content
MilliporeSigma
All Photos(4)

Key Documents

N1127

Sigma-Aldrich

2-Nitrophenyl β-D-galactopyranoside

≥98% (enzymatic)

Synonym(s):

ONPG , o-Nitrophenyl β-D-galactopyranoside, ONPG

Sign Into View Organizational & Contract Pricing


About This Item

Empirical Formula (Hill Notation):
C12H15NO8
CAS Number:
Molecular Weight:
301.25
Beilstein/REAXYS Number:
92207
EC Number:
MDL number:
UNSPSC Code:
12352200
PubChem Substance ID:
NACRES:
NA.52

grade

for molecular biology

Quality Level

assay

≥98% (enzymatic)

form

powder

storage temp.

−20°C

SMILES string

OC[C@H]1O[C@@H](Oc2ccccc2[N+]([O-])=O)[C@H](O)[C@@H](O)[C@H]1O

InChI

1S/C12H15NO8/c14-5-8-9(15)10(16)11(17)12(21-8)20-7-4-2-1-3-6(7)13(18)19/h1-4,8-12,14-17H,5H2/t8-,9+,10+,11-,12-/m1/s1

InChI key

KUWPCJHYPSUOFW-YBXAARCKSA-N

Looking for similar products? Visit Product Comparison Guide

General description

ONPG (2-Nitrophenyl β-D-galactopyranoside) is a colorimetric substrate for β-galactosidase.

Application

2-Nitrophenyl β-D-galactopyranoside is an enzyme substrate used to detect lacZ activity and hence the presence of β-galactosidase.

Biochem/physiol Actions

β-galactosidase, breaks down lactose into galactose and glucose. β-Galactosidase is not lactose specific and can act on simple galactosides. 2-Nitrophenyl β-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.

Principle

β-galactosidase, breaks down lactose into galactose and glucose. β-Galactosidase is not lactose specific and can act on simple galactosides. 2-Nitrophenyl β-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.

Substrates

Chromogenic substrate for β-galactosidase

Storage Class

11 - Combustible Solids

wgk_germany

WGK 3

flash_point_f

Not applicable

flash_point_c

Not applicable

ppe

Eyeshields, Gloves, type N95 (US)


Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library

D R Henderson et al.
Clinical chemistry, 32(9), 1637-1641 (1986-09-01)
Genetic engineering of beta-galactosidase (EC 3.2.1.23) has led to the development of a new homogeneous assay system, CEDIA. The Z gene of the lac operon of Escherichia coli encodes a large enzymatically inactive polypeptide that spontaneously aggregates and folds to
Steven T Bruckbauer et al.
PloS one, 14(1), e0199482-e0199482 (2019-01-24)
We have previously generated four replicate populations of ionizing radiation (IR)-resistant Escherichia coli though directed evolution. Sequencing of isolates from these populations revealed that mutations affecting DNA repair (through DNA double-strand break repair and replication restart), ROS amelioration, and cell
Superimposition of temperature regulation on yeast promoters.
A Z Sledziewski et al.
Methods in enzymology, 185, 351-366 (1990-01-01)
Receptor-mediated transport of DNA into eukaryotic cells.
M Cotten et al.
Methods in enzymology, 217, 618-644 (1993-01-01)
Gabriela N Tenea et al.
Foods (Basel, Switzerland), 9(9) (2020-09-10)
A novel Weissella cibaria strain UTNGt21O from the fruit of the Solanum quitoense (naranjilla) shrub produces a peptide that inhibits the growth of both Salmonella enterica subsp. enterica ATCC51741 and Escherichia coli ATCC25922 at different stages. A total of 31

Articles

Transformation introduces exogenous DNA into cells, a fundamental genetic modification process demonstrated in Streptococcus pneumoniae.

Protocols

Yeasts are considered model systems for eukaryotic studies as they exhibit fast growth and have dispersed cells.

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service