X-Gal
X-Gal
Invitrogen™

X-Gal

X-Gal (5-bromo-4-chloro-3-indolyl-β-D-galactoside) is a histochemical substrate for β-galactosidase. This substrate yields a blue precipitate upon hydrolysis, making it suitable for use in immunoblotting or immunocytochemical assays.
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Catalog NumberQuantityProduct Type
155200181 gX-Gal Substrate
15520034100 mgX-Gal Substrate
Catalog number 15520018
Price (CNY)
2,678.00
Each
Add to cart
Quantity:
1 g
Product Type:
X-Gal Substrate
Price (CNY)
2,678.00
Each
Add to cart
X-Gal (5-bromo-4-chloro-3-indolyl-β-D-galactoside) is a histochemical substrate for β-galactosidase. This substrate yields a blue precipitate upon hydrolysis, making it suitable for use in immunoblotting or immunocytochemical assays. Bacteria containing active β-galactosidase produce blue colonies when grown on plates containing X-Gal. X-Gal is supplied as white crystals and is soluble in dimethylformamide.

Primary applications

  • Blue-white screening—detect functional β-galactosidase (reporter gene expression)
  • Histochemical detection of β-galactosidase activity in fixed tissues
  • X-gal overlay assay

Find the media format that fits your needs

We offer many ready-to-use media formulations, such as LB Broth (10855001), Terrific Broth (A1374301) or S.O.C recovery medium (15544034).

We also offer IPTG (15529019) for blue-white screening.

Explore other media formats for bacterial growth.

For Research Use Only. Not for use in diagnostic procedures.
Specifications
Chemical Name or Material5-bromo-4-chloro-3-indolyl-β-D-galactoside
DescriptionX-Gal, Cell-Permeant
For Use With (Application)Immunoblotting
Product TypeX-Gal Substrate
Quantity1 g
Shipping ConditionApproved for shipment at Room Temperature or on Wet Ice
Detection MethodColorimetric
FormPowder
FormatBottle
Unit SizeEach
Contents & Storage
• X-Gal, powder, 1 g

Frequently asked questions (FAQs)

Can X-gal be resuspended in dimethylsulfoxide (DMSO) instead of dimethylformamide (DMF)? How are X-gal plates prepared for blue/white screening?

X-gal (also known as 5-bromo-4-chloro-3-indolyl-?-D-galactoside) is soluble in either DMSO or DMF, and can be stored in solution in the freezer for up to 6 months. Protect the solution from light.

To add X-gal to previously made agar plates, pipette 40 ?l of a 40 mg/ml stock solution onto a 100mm pre-poured agar plate and spread evenly with a sterile spreader. Let dry 15 minutes and store plates away from light.

How do I resuspend IPTG and X-Gal?

IPTG can be reconstituted in water. Make a stock of 100 mM in water and store working aliquots at -20°C. X-gal can be reconstituted in DMSO, or in a 50:50 mix of DMSO and water. To do the latter, you must dissolve in DMSO first, and then add water to bring up to final volume. It is not necessary to filter sterilize these solutions.

The X-gal solution should be protected from light. To make plates, add 50 ug/ml X-gal and 1 mM (0.24 mg/mL) IPTG to LB/agar that has been cooled down to 50°C. To spread on top of plates, use 50 µl 2% stock of X-gal and 30 µl 100 mM stock of IPTG. 

Find additional tips, troubleshooting help, and resources within our Protein Expression Support Center.