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Specifications:
| Application | Colorimetric Assay | ||
| Storage Temperature | -20°C | ||
| Product Type | Enzymes and Substrates | Forms | Solid |
| Product Brand | Thermo Fisher Scientific™ | ||
| Product Grade | Molecular Biology | Formula | C₁₄H₁₅BrClNO₆ |
Chromogenic substrate for β-galactosidase detection in blue/white screening and histochemical assays
Thermo Scientific™ X-Gal is an inert, chromogenic β-galactosidase substrate widely used in blue/white colony screening, lacZ reporter assays, and histochemical detection procedures. Upon hydrolysis by β-galactosidase, X-Gal is cleaved into colorless galactose and 4-chloro-3-bromo-indigo, the latter forming an intense blue precipitate for easy visual detection.
When combined with IPTG to induce lacZ expression, X-Gal enables efficient differentiation between recombinant colonies (white) and non-recombinant colonies (blue) in molecular cloning workflows.
Key Features
- High Contrast Detection – Produces a strong blue precipitate upon hydrolysis
- Versatile Applications – For colony screening, reporter gene assays, and histochemistry
- Reliable Performance – Consistent color development with clear discrimination
- Flexible Preparation – Recommended 20 mg/mL stock in DMF or DMSO
Applications
- Blue/white colony screening in molecular cloning
- Visualization of β-galactosidase activity in transfected eukaryotic cells
- Histochemical staining for β-galactosidase expression in tissues
- Immunological and in situ detection of β-galactosidase reporter activity
Usage Notes
- Prepare stock solution in dimethylformamide (DMF) or dimethylsulfoxide (DMSO) at 20 mg/mL
- DMF may dissolve certain plastics—avoid direct contact with plastic Petri dishes
- DMF is toxic—ensure complete drying of DMF-containing solution before plating bacteria
Specifications
| Parameter | Details |
|---|---|
| Catalog Numbers | R0404 (1 g), R0402 (2 × 1 g) |
| Substrate Type | β-Galactosidase substrate (X-Gal) |
| Detection Method | Colorimetric |
| Form | Solid |
| Unit Size | Each |
| Substrate Properties | Chemical substrate |
| Storage Conditions | Store at room temperature |
| Regulatory Status | Research Use Only (RUO) |
Thermo Scientific™ X-Gal is a gold-standard chromogenic substrate for β-galactosidase detection, delivering high visual contrast and reliability in both molecular cloning and histochemical applications.
- Pack Size: 1g 2 x 1 g