Blue-White Select™ Screening Reagent
SIGMA/B3928 - for selection of recombinant bacterial clones
Synonym: Blue-White Reagent; Screening Reagent; Selection Reagent
Product Type: Chemical
Blue-white color selection of DH5α cells using X-gal.
| form | liquid |
| grade | Molecular Biology |
| Quality Level | 200  |
| shipped in | dry ice |
| storage temp. | −20°C |
| suitability | suitable for nucleic acid staining |
| technique(s) | nucleic acid detection: suitable |
| usage | sufficient for 125 dishes (90 mm) |
| Biochem/physiol Actions: | When Blue-White Select™ Screening Reagent is cleaved by β-galactosidase, the resulting product will form a blue precipitate. Lac+ colonies grown in the presence of Blue-White Select™ Screening Reagent remain white in color, allowing for easy differentiation between lac+ and lac- colonies. The technique is based on vectors such as the pUC and the M13mp series that carry a fragment of the β-galactosidase gene encoding an a-fragment of β-galactosidase. Exploitation of these vectors requires use of a bacteria strain carrying the complementing gene fragment to allow the assembly of an active complex, resulting in the formation of blue colonies. Disruption of the ß-galactosidase gene by insertion of a DNA fragment into the vector′s multiple cloning site results in the loss of functional β-galactosidase activity; these colonies remain white, allowing for easy differentiation between lac+ and lac- colonies. |
| Features and Benefits: | • Intense color contrast for easy colony selection • Convenient, ready-to-use solution |
| General description: | Sigma’s Blue-White Select™ Screening Reagent is a chromogenic substrate for β-galactosidase, used to determine the presence or absence of a cloned DNA insert in bacteria growing on agar plates. Blue-White Select™ Screening Reagent is designed for blue-white selection of recombinant bacterial colonies with the lac+ phenotype. |
| Legal Information: | Blue-White Select is a trademark of Sigma-Aldrich Co. LLC |
| Other Notes: | 40 mg/mL IPTG 40 mg/mL X-Gal (prepared in DMSO) |
| RIDADR | NONH for all modes of transport |
| WGK Germany | WGK 3 |
| Flash Point(F) | 188.6 °F |
| Flash Point(C) | 87 °C |
| Storage Temp. | −20°C |
| UNSPSC | 12352200 |