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  • β1-4 Galactosidase


    Substrate Specificity:
    β1-4 Galactosidase is a highly specific exoglycosidase that catalyzes the hydrolysis of β1-4 linked D-galactopyranosyl residues from oligosaccharides.

    Detailed Specificity: Specificity can vary depending on incubation time and branching structure.
    A. 0.1 nm/µl substrate, 2 units, 1 hr incubation
    B. 0.1 nm/µl substrate, 4 units, 1 hr incubation
    C. 0.1 nm/µl substrate, 8 units, 1 hr incubation
    Figure 1:
    Detailed specificity of β1-4 Galactosidase. Reactions (A), (B) and (C) contained 2 units, 4 units and 8 units of β1-4 Galactosidase, respectively, and either 1X G4 or 1X G6 Reaction Buffer in a total reaction volume of 10 µl. Reactions were incubated at 37°C.

    Product Source

    Cloned from Bacteroides fragilis and expressed in E.coli (1).

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C)Concentration
    G4 Reaction Buffer10X

    Properties and Usage

    Unit Definition

    One unit is defined as the amount of enzyme required to cleave > 95% of the terminal, β-D-galactose from 1 nmol Galβ1-4GlcNAcb1-3Galβ1-4Glc-7-amino-4-methyl-coumarin (AMC), in 1 hour at 37°C in a total reaction volume of 10 µl.

    Unit Definition Assay: Two fold serial dilutions of β1-4 Galactosidase are incubated with 1 nmol AMC-labeled substrate in 1X G4 Reaction Buffer, in a 10 µl reaction. The reaction mix is incubated for 1 hour at 37°C. Separation of reaction products are visualized via thin layer chromatography (2).

    Reaction Conditions

    1X G4 Reaction Buffer
    Incubate at 37°C

    1X G4 Reaction Buffer:
    50 mM sodium citrate
    100 mM NaCl
    pH 6 @ 25°C

    Storage Temperature


    Storage Conditions

    20 mM Tris-HCl
    50 mM NaCl
    1 mM Na2EDTA
    pH 7.5 @ 25°C

    Heat Inactivation

    65°C for 10 min

    Molecular Weight

    Apparent: 94000 daltons

    Quality Control

    Quality Assurance Statement

    • No contaminating exoglycosidase or proteolytic activity could be detected.

    Quality Control Assays

    The following Quality Control Tests are performed on each new lot and meet the specifications designated for the product. Individual lot data can be found on the Product Summary Sheet/Datacard or Manual which can be found in the Supporting Documents section of this page.
    • Glycosidase Activity (TLC):
      The product is tested in multiple reactions, each containing a fluorescently-labeled oligosaccharide or glycopeptide.  The reaction products are analyzed by TLC for digestion of substrate. No contaminating exoglycosidase or endoglycosidase activity is detected.
    • Protease Activity (SDS-PAGE):

      The product is tested for protease activity by incubation with a standard mixture of proteins resulting in no detectable degradation of the proteins as determined by SDS-PAGE.

    • Protein Purity (SDS-PAGE):
      The physical purity is assessed by comparing contaminating protein bands in a concentrated sample to the protein of interest band in a sample of known dilution. The purity is determined by SDS-PAGE.


    1. McLeod, E. New England Biolabs, Inc., unpublished observations.
    2. Wong-Madden, S.T. and Landry, D. (1995). Glycobiology. 5, 19-28.

    Supporting Documents

    Material Safety Datasheets

    The following is a list of Material Safety Data Sheets (MSDS) that apply to this product to help you use it safely. The following file naming structure is used to name these document files: [Product Name] MSDS. For international versions please contact us at info@neb.com.


    The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at info@neb.com or fill out the Technical Support Form for appropriate document.
    1. Can I use β1-4 Galactosidase in a double digest with other exoglycosidases and/or endoglycosidases?
    2. What is the difference between β1-4 Galactosidase and β1-3 Galactosidase?
    3. What is a good positive control for β1-4 Galactosidase?
    4. What are glycosidases and their uses?
    5. How much exoglycosidase should be used?
    1. Typical Reaction Conditions for β1-4 Galactosidase (P0730)

    Usage Guidelines & Tips

    ß 1-4 Galactosidase (P0730)

    A good positive control for ß 1-4Gal is pNP-ßGal

    Using 1-2 µl is a good starting point for a 1 hr incubation of 1µg of glycoprotein or 100 nM of oligosaccharide.

    ß 1-4 Gal can be used in double digests with other exoglycosidases using G6 Reaction Buffer