GelGreen™ can be imaged on a UV transilluminator or blue light source using SYBR® dye settings
A number of ethidium bromide alternatives are marketed as being safe. In fact, many so-called “safe” gel stains contain dyes that are well known to bind DNA in living cells, with cytotoxic effects.
GelRed™ and GelGreen™ are designed to be nontoxic and nonmutagenic by virtue of being cell membrane impermeable, so they cannot enter living cells. Download our white paper to learn more: Comparison of Nucleic Acid Gel Stains: Cell permeability, safety, and sensitivity of ethidium bromide alternatives.
GelRed™ and GelGreen™ are a new generation of fluorescent DNA stains designed to replace the highly toxic ethidium bromide (EtBr). Developed by scientists at Biotium, GelRed™ and GelGreen™ are superior to EtBr and other ethidium bromide alternatives by having a combination of low toxicity, high sensitivity and exceptional stability.
GelRed™ Is Superior to EtBr
Comparison of ethidium bromide (EtBr) and GelRed in precast gel staining using 1% agarose gel in TBE buffer. Two-fold serial dilutions of 1 kb Plus DNA Ladder (Invitrogen) were loaded in the amounts of 200 ng, 100 ng, 50 ng and 25 ng from left to right. Gels were imaged using 300 nm transilluminator and photographed with an EtBr filter.
GelGreen™ Is Unmatched by SYBR® Safe
Comparison of GelGreen and SYBR Safe in post-electrophoresis staining of 1% agarose/TBE gels. Two-fold serial dilutions (200 ng, 100 ng, 50 ng and 25 ng) of 1 kb Plus DNA Ladder (Invitrogen). Gels were imaged using 254-nm UV transilluminator and photographed with a SYBR filter.
EtBr has been the predominant dye used for nucleic acid staining for decades because of its low price and generally sufficient sensitivity. However, EtBr is a highly mutagenic material. The safety hazard and costs associated with decontamination and waste disposal can ultimately make the nucleic acid dye expensive to use. For this reason, various ethidium bromide alternative DNA gel stains have become commercially available in recent years. Although these alternative nucleic acid staining dyes have reduced mutagenicity, they often have to sacrifice other aspects of the dyes. For example, SYBR® Safe has very limited sensitivity while SYBR® Green and SYBR® Gold are much less stable than EtBr.
To make GelRed™ and GelGreen™ safe, scientists at Biotium used a novel yet very simple concept: reduce genotoxicity by preventing the dyes from entering living cells. We believe that a DNA-binding dye can be made nonmutagenic or substantially so by denying its chance to be in contact with genomic DNA in living cells. Thus, we engineered the chemical structures of GelRed™ and GelGreen™ such that the dyes are incapable of crossing cell membranes. The Ames test confirmed that GelRed™ and GelGreen™ are nonmutagenic at concentrations well above their working concentrations used for gel staining. Furthermore, environmental safety tests showed that GelRed™ and GelGreen™ are nonhazardous and nontoxic to aquatic life. As a result, GelRed™ and GelGreen™ can be disposed of down the drain or thrown away in the regular trash. For more information, please download the GelRed™/GelGreen™ Safety Report.
GelRed™ and GelGreen™ are highly sensitive either as precast gel stains or post gel stains. GelRed™ is much more sensitive than EtBr, and at least as sensitive as or brighter than SYBR® Gold in post gel staining. Unlike SYBR® Gold, GelRed™ can also be used as a highly sensitive precast gel stain. GelGreen™ is spectrally similar to SYBR® Safe but is far more sensitive, and can be used with blue light gel imaging systems like the DarkReader®. PAGE GelRed and PAGE GelGreen are designed for staining DNA in acrylamide gels.
Another major advantage of GelRed™ and GelGreen™ DNA stain is their remarkable stability. You can store and handle the two nucleic acid staining dyes the same way you do with EtBr.
GelRed™ and GelGreen™ troubleshooting
Many customers use GelRed™ or GelGreen™ precast gels for convenience. However, because GelRed™ and GelGreen™ are high affinity dyes designed to be larger dyes to improve their safety, they can affect the migration of DNA in precast gels. Some samples, such as restriction digested DNA may migrate abnormally in GelRed™ or GelGreen™ precast gels.
Tip #1: Load less DNA
Smearing and smiling in GelRed™ or GelGreen™ precast gels most often caused by overloading of DNA. If you see band migration shifts or smearing and smiling, try reducing the amount of DNA loaded. The recommended loading amount for ladders and samples of known concentration is 50-200 ng/lane. For samples of unknown concentration, try loading one half or one third of the usual amount of DNA. This usually solves band migration problems.
Tip #2: Try the post-staining protocol
To avoid any interference the dye may have on DNA migration, we recommend using the post-staining protocol. If your application requires loading more than the recommended amount of DNA, use the post-staining protocol. While we recommend post-staining gels for 30 minutes, you may be able see bands in as little as five minutes, depending on how much DNA is present. Post-staining solutions can be reused. See the GelRed™ Product Information Sheet or GelGreen™ Product Information Sheet for detailed protocols.
Other tips to improve agarose gel resolution:
- If you see DNA migration issues or smearing after post-staining with GelRed or GelGreen, then the problem is not caused by the nucleic acid dye. Avoid overfilling gel wells to prevent smearing of DNA down the surface of the gel.
- Pour a lower percentage agarose gel. Higher molecular weight DNA separates better with a lower percentage gel.
- Change the running buffer. TBE buffer has a higher buffering capacity than TAE buffer.
The dye may have precipitated out of solution.
- Heat GelRed™ solution to 45-50°C for two minutes and vortex to dissolve.
- Store dye at room temperature to avoid precipitation.
GelRed™ and GelGreen™ Nucleic Acid Gel Stains
The main difference between GelRed™ and GelGreen™ is their fluorescence excitation and emission wavelengths. GelRed™ has red fluorescence, similar to ethidium bromide. GelGreen™ has green fluorescence, similar to SYBR® Green or SYBR® Safe. Both dyes are compatible with standard UV transilluminators. GelGreen™ is also compatible with blue light transilluminators, which allow users to avoid exposing themselves and their DNA samples to ultraviolet radiation.
GelRed™ and GelGreen™ have higher sensitivity for double stranded nucleic acids compared to single stranded nucleic acids, but GelRed™ is more sensitive for staining single stranded nucleic acids than GelGreen™. GelRed™ is about twice as sensitive for double stranded nucleic acids compared to single-stranded nucleic acids, and about five times more sensitive than GelGreen™ for staining single stranded nucleic acids.
For more information about these products, please visit our DNA stains technology page.
View the GelRed™ Product Line
View the GelGreen™ Product Line← FAQs
The water formulation is a newer and improved product compared to the stock in DMSO. We recommend using dyes in water to avoid the potential hazards of handling DMSO, which can be absorbed through the skin. We continue to offer dyes in DMSO because some users do not wish to alter their established laboratory protocols. Based on internal testing, both formulations perform similarly.← FAQs
GelRed™ is compatible with a standard UV transilluminator (302 or 312 nm).
GelGreen™ has sufficient absorption between 250-300 nm and a strong absorption peak at around 500 nm. GelGreen™ is compatible with a 254 nm UV transilluminator or a gel reader with visible light excitation such as a Dark Reader or a 488 nm laser gel scanner.