In molecular cloning, a key question is: how to quickly distinguish which colonies carry recombinant plasmids and which do not?

The classic blue-white screening system accomplishes this process using the α-peptide complementation principle of the lacZ gene.

In vectors containing the lacZ gene (encoding the α-fragment of β-D-galactosidase), researchers insert the exogenous DNA fragment into the multiple cloning site region of the lacZ gene. When the exogenous DNA is successfully inserted, the lacZ gene is disrupted and cannot produce functional β-D-galactosidase.

At this point, the chromogenic substrate in the medium comes into play.

For the traditional system using X-Gal: colonies without exogenous DNA insertion (lac⁺) produce β-D-galactosidase, which hydrolyzes X-Gal to generate a blue product; while positive clones with exogenous DNA insertion (lac⁻) remain white—this is the origin of "blue-white screening".

Magenta-Gal has a similar detection logic to X-Gal, but its chromogenic product is magenta, providing another color choice for the traditional blue system. lac⁺ colonies hydrolyze Magenta-Gal to produce a magenta product.

Therefore, the "magenta colonies" seen in experiments are colored precipitates formed after β-D-galactosidase hydrolyzes the substrate. The entire signal conversion process can be summarized as:

lacZ gene expression → β-D-galactosidase production → Magenta-Gal hydrolysis → magenta precipitate formation

Thus, through the difference between colored and colorless, it provides an intuitive chromogenic signal for recombinant clone screening. Compared with traditional blue/white, magenta provides higher color contrast on certain medium backgrounds, offering researchers another intuitive choice for screening recombinant clones.

Magenta-Gal is a classic chromogenic substrate for β-D-galactosidase. It links a chromogenic indole group to β-D-galactose via a glycosidic bond, keeping the chromogenic group "hidden" in the substrate state; only after β-D-galactosidase recognizes and hydrolyzes the substrate is it released and further forms a colored precipitate.

Taking clone screening in molecular cloning as an example, this process can be summarized in three steps:

1. Substrate recognition: The β-D-galactoside structure in Magenta-Gal is recognized by β-D-galactosidase, and the enzyme binds to the substrate and enters the catalytic process.

2. Enzymatic hydrolysis: β-D-galactosidase hydrolyzes the β-D-glycosidic bond in Magenta-Gal, releasing an indole chromogenic intermediate.

3. Oxidative color development: The released indole chromogenic intermediate undergoes oxidative dimerization in air, forming a water-insoluble magenta precipitate.

Chinese Name: 5-Bromo-6-chloro-3-indolyl β-D-galactopyranoside

English Name: 5-Bromo-6-chloro-3-indolyl β-D-galactopyranoside

Abbreviation: Magenta-Gal

CAS Number: 93863-88-8

Molecular Formula: C14H15BrClNO6

Molecular Weight: 408.63

Specifications: 1 g / 25 g / 100 g (Custom packaging supported)

Form: Lyophilized powder

Product Number: G01020003

Stock: In stock

Color: Magenta

To meet the differentiated needs of various detection systems, GeneSeqTools Bioscience & Technology also offers a series of β-D-galactosidase substrates covering multi-color chromogenic and fluorescent readouts:

1. CAS: 7240-90-6, X-Gal

2. CAS: 126787-65-3, Y-Gal

3. CAS: 93863-88-8, Magenta-Gal

4. CAS: 138182-21-5, Salmon-Gal

5. CAS: 95079-19-9, Resorufin-Gal

6. CAS: 6160-78-7, 4MU-Gal

7. CAS: 97753-82-7, Blue-Gal

8. CAS: 36473-36-6, Purple-Gal

9. CAS: 207727-11-5, Rouge-Gal

10. CAS: 207598-26-3, Green-Gal

As a classic β-D-galactosidase substrate, Magenta-Gal not only meets the chromogenic needs in molecular cloning but can also be used for microbial detection and related system development. Specific application scenarios are as follows:

1. Recombinant clone screening and lacZ chromogenic detection

Used for screening and result interpretation of recombinant bacterial clones. In the LacZ screening system, colonies with β-D-galactosidase activity form a magenta signal, while colonies lacking enzyme activity remain white, helping researchers quickly complete recombinant clone screening.

2. Development of microbial chromogenic media and strain identification

As an enzyme substrate raw material in the development of microbial chromogenic media, it utilizes differences in β-D-galactosidase activity among different strains to achieve colony color differentiation.

Mainly covers:

• Detection and identification of coliforms: β-D-galactosidase produced by coliforms catalyzes the hydrolysis of Magenta-Gal, forming a magenta or purple-red colony signal. In commercial media, Magenta-Gal is often used in combination with substrates such as X-GLUC to achieve simultaneous differentiation of coliforms and E. coli through color differences.

• Formulation development of chromogenic media for multi-parameter parallel detection: Utilizing the color differences between Magenta-Gal's magenta, X-Gal's blue, and Salmon-Gal's salmon red, it supports simultaneous identification of multiple targets on the same plate.

3. β-Gal-related enzyme activity analysis

In solution systems, Magenta-Gal forms an insoluble magenta precipitate after hydrolysis by β-D-galactosidase, and the signal can be read by eye or instrument, suitable for the establishment and validation of enzyme activity assay methods.

✅ Batch-to-batch stability and large-scale supply

The synthesis process of β-D-galactosidase chromogenic substrates undergoes strict quality control. GeneSeqTools Bioscience & Technology has large-scale production capacity, supporting full-chain substrate supply from R&D to large-scale production.

✅ Magenta signal with higher recognizability on specific backgrounds

Magenta-Gal produces a magenta precipitate after hydrolysis. Compared with the blue/white system of X-Gal, the magenta/white contrast is more distinct on certain medium backgrounds.

✅ Colored precipitate does not diffuse, enabling precise signal localization

Magenta-Gal forms a stable colored precipitate after the action of β-D-galactosidase, with clear color, facilitating colony identification and experimental result observation, helping to improve screening efficiency.

✅ Orthogonal color spectrum, supporting multi-parameter parallel detection

The magenta signal formed by Magenta-Gal can be combined with blue, salmon red, and other chromogenic systems, providing more color design space for multi-parameter detection and chromogenic medium development.

✅ In-stock direct shipment with controllable cost

GeneSeqTools Bioscience & Technology keeps Magenta-Gal in stock, eliminating long lead time waits; competitive pricing effectively reduces overall raw material procurement costs.