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  • Gel Loading Dye, Purple (6X)


    Gel Loading Dye, Purple (6X) is a pre-mixed loading buffer which contains a combination of two dyes, Dye 1 (pink/red) and Dye 2 (blue). The red dye serves as the tracking dye for both agarose and non-denaturing polyacrylamide gel electrophoresis. The two dyes separate upon gel electrophoresis; the red band is the major indicator and migrates similarly to Bromophenol Blue on agarose gels. Specifically chosen, this dye does not leave a shadow under UV light. This solution contains SDS, which often results in sharper bands, as some restriction enzymes are known to remain bound to DNA following cleavage. EDTA is also included to chelate magnesium (up to 10 mM) in enzymatic reactions, thereby stopping the reaction. The dye also contains Ficoll, which creates brighter and tighter bands when compared to glycerol loading dyes.

    Comparison of dye fronts
    Nucleic acid samples were run on an agarose gel, with either Purple or Blue loading dyes. Both dyes ran at the same speed.
    UV shadow comparison
    The new Gel Loading Dye, Purple (6X) does not cast a UV shadow over the underlying bands, unlike the Gel Loading Dye, Blue (6X).

    Advantages and Features


    • No UV shadow allows for publication grade images
    • Brighter, sharper bands vs. glycerol-based loading dyes
    • Stops enzyme reactions

    Properties and Usage

    Storage Temperature


    1X Buffer Components

    2.5% Ficoll®-400
    10mM EDTA
    3.3mM Tris-HCl
    0.08% SDS
    0.02% Dye 1
    0.001% Dye 2
    pH 8.0@25°C

    Quality Control

    Quality Assurance Statement

    • Gel Loading Dye, Purple (6X) is assayed for Non-Specific DNase Activity (16 hour), Exonuclease Activity (Radioactivity Release), Endonuclease Activity (Nicking) and RNase Activity (Extended Digestion).


    1. Use 5 μl of Gel Loading Dye, Purple (6X) per 25 μl reaction, or 10 μl per 50 μl reaction. Mix well before loading gel.

    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. Does the Gel Loading Dye, Purple have any advantages over the traditional Blue Loading Dye?
    2. How many bands of color should I see on the gel?
    3. I cannot see the blue dye when I run it on a gel. Why not?
    4. Why is there SDS in the dye?
    5. Can I use the Gel Loading Dye, Purple with the QIAquick Gel Extraction Kit?
    6. Is Gel Loading Dye, Purple (6x) compatible with other systems such as SYBR® and GelRed during gel electrophoresis?
    1. In vitro digestion of DNA with Cas9 Nuclease, S. pyogenes (M0386)