DNA fragments stained with nucleic acid gel stain

In gel electrophoresis, fluorescent nucleic acid gel stains are dyes used for DNA detection. When bound to DNA molecules and illuminated with UV or blue light, these dye molecules fluoresce brightly. Once the gel is stained, transilluminators are used to excite the dye molecules, which allow DNA to be visualized, sized, and quantified. The SYBR family of dyes is a safer and more sensitive alternative to ethidium bromide (EtBr).

DNA stains selection guide

 UltraPure Ethidium BromideSYBR Safe DNA Gel StainSYBR Green I Nucleic Acid Gel StainSYBR Gold Nucleic Acid Gel Stain
Best forDetection of nucleic acids in agarose gels and CsCl gradientsSafer, smarter alternative to EtBrUltimate sensitivity for capillary electrophoresis and real-time PCRUltimate sensitivity for DNA detection
Sensitivity with dsDNASensitive
(1 ng)
(3 ng)
Highly sensitive
(>60 pg)
Ultra sensitive
(>25 pg)
Available as ready-to-use   
Recommended for gel electrophoresis✓ ✓  ✓ 
Recommended for ssDNA   ✓ 
Improved cloning efficiency; avoid UV-induced nicked DNA ✓ ✓ ✓ 
Package sizes
  • 0.5 mL
  • 1 mL
  • 20 x 50 µL
  • 0.5 mL
Detection methodUVUV or blue lightFluorescence (blue light excitation)UV, blue light, or laser scanners

SYBR Gold nucleic acid gel stain

Gel stained with SYBR Gold DNA gel stain and visualized with Dark Reader transilluminator

SYBR Gold stain is a versatile and universal nucleic acid gel stain that provides excellent sensitivity for dsDNA, ssDNA, and RNA detection. SYBR Gold stain can be used with many gel types and does not require a wash step.

SYBR Gold stain is an excellent choice for use in molecular biology applications such as northern blotting, denaturing gradient gel electrophoresis, and single-strand conformation polymorphism, as well as routine gel analysis.

SYBR Gold stain offers multiple benefits when compared to other post-electrophoresis stains, including:

  • Detection of as low as 25 pg of DNA, which renders maximum sensitivity
  • Faster penetration of agarose gels and staining of thicker, high percentage gels 
  • Low background fluorescence, owing to the low intrinsic fluorescence of the unbound dye
  • No interference of unbound dye molecules with restriction endonuclease or ligase activity nor with subsequent PCR reactions

Shop for SYBR Gold stains

SYBR Green I Nucleic Acid Gel Stain

SYBR Green I Nucleic Acid Gel Stain is an extremely sensitive fluorescent stain for detecting nucleic acids in both agarose and polyacrylamide gels, detecting as little as 60 pg of DNA. SYBR Green stains and SYBR Gold stains share many similarities, but SYBR Green stains are slightly less sensitive than SYBR Gold stain.

SYBR Green I stain has some important qualities, making it the preferred reagent for certain applications. 

  • Exhibits greater fluorescence enhancement when bound to dsDNA and oligonucleotides than when bound to RNA; this makes SYBR Green I the ideal candidate for staining DNA in applications where RNA may be present and obscure the results
  • Has a very low background fluorescence, making it the preferred dye for some laser scanning instruments where background fluorescence can produce unacceptable noise levels

Shop SYBR Green I Nucleic Acid Gel Stain
Learn more about SYBR Green II RNA Gel Stain

gel stained with SYBR Green I DNA Gel stain and visualized using 254 nm epi illumination pen

SYBR Safe DNA Stain
gel stained with SYBR Safe DNA Gel stain

SYBR Safe DNA gel stain is the safest reagent for staining DNA. SYBR Safe stain has sensitivity comparable to that of EtBr, yet tests negative in three mammalian cell-based assays for genotoxicity. It is less mutagenic than ethidium bromide in standard Ames tests and is not classified as hazardous waste under U.S. federal regulations.

Learn more about SYBR Safe DNA stains

Additional resources for DNA stains


Nucleic acid electrophoresis products
Explore Thermo Fisher Scientific’s suite of products for all your electrophoresis needs.

Nucleic acid electrophoresis education
Learn about gel electrophoresis basics, workflow, considerations, applications, and troubleshooting for separation and analysis of nucleic acids.

DNA and RNA protocols
Find easy-to-follow protocols for everyday experiments, including agarose protocols and mRNA protocols.


Nucleic acid purification and analysis support center
Find tips, troubleshooting help, and resources for your nucleic acid purification and analysis applications.

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For additional questions, reach out to our Technical Application Scientists.

For Research Use Only. Not for use in diagnostic procedures.

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