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2-Nitrophenyl b-D-galactopyranoside
| CAS No: | 369-07-3 |
| Product Code: | EN06363 |
| Chemical Formula: | |
| Molecular Weight: | 301.25 |
| Product Structure
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| Pack Size | Pack Price | Hazardous Surcharge | Special Packaging | Number of Packs |
| 10g | $80.00 £56.00 €64.80 | Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable | Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable | |
| 25g | $150.00 £105.00 €121.50 | Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable | Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable | |
| 50g | $200.00 £140.00 €162.00 | Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable | Not Applicable Not Applicable Not Applicable Not Applicable Not Applicable | |
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ONPG
ONPG is the common abbreviation for (ortho) 2-Nitrophenyl-β-D-galactopyranoside.
ONPG is used in colourimetric and spectrophotometric assays for the detection of β-galactosidase activity which are of interest in clinical, environmental, food and molecular biology arenas.1 ONPG is hydrolysed by β-galactosidase to yield galactose and ortho-Nitrophenol, which is yellow in colour and absorbs light at 420 nm. The intensity of the colour can be used to determine the rate at which β-galactosidase can hydrolyse lactose. The impact of experimental factors on the reproducibility of β-galactosidase assays has been reported.2
In common with several other β-galactosidase substrates such as X-Gal, ONPG does not act as an inducer of genes under the control of the lac operon in bacteria such as E. coli. In the absence of a lactose analogue such as IPTG (Product Code: E10593 I) transcription of β-galactosidase will not take place and ONPG will not be hydrolysed.
Refs:
1. J Lederberg, J. Bacteriol., 1950, 20, 137.
2. A Giacomini et al, FEMS Microbiol. Lett., 2006, 100, 87.