SYBR green

SYBR Green I
CAS number 163795-75-3 YesY
PubChem 10436340
Molecular formula C32H37N4S+
Molar mass 509.73 g·mol−1
Solubility Soluble in Dimethylsulfoxide
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

SYBR® Green I (SG) is an asymmetrical cyanine dye[1] used as a nucleic acid stain in molecular biology. The SYBR® family of dyes is produced by Molecular Probes,Inc., wholly owned subsidiary of Life Technologies Corporation. SYBR® Green I binds to DNA. The resulting DNA-dye-complex absorbs blue light (λmax = 497 nm) and emits green light (λmax = 520 nm). The stain preferentially binds to double-stranded DNA, but will stain single-stranded DNA with lower performance. SYBR® Green can also stain RNA with a lower performance than DNA.


SYBR® Green finds usage in several areas of biochemistry and molecular biology. It is used as a dye for the quantification of double stranded DNA in some methods of quantitative PCR.[2] It is also used to visualise DNA in gel electrophoresis. Higher concentrations of SYBR® Green can be used to stain agarose gels in order to visualise the DNA present. In addition to labelling pure nucleic acids SYBR® Green can also be used for labelling of DNA within cells for flow cytometry and fluorescence microscopy. In these cases RNase treatment may be required to reduce background from RNA in the cells.


SYBR® Green I is marketed as a replacement for the potential human mutagen ethidium bromide, as both safer to work with and free from the complex waste disposal issues of ethidium. However any small molecule capable of binding DNA with high affinity is a possible carcinogen, including SYBR® Green.

In a study using the Ames test, which measures the ability of chemicals to cause mutations, when assayed at the same concentration there was no clear pattern in the relative mutagenicities of ethidium bromide and SYBR® green I.[3] Ethidium bromide was more mutagenic at higher concentrations.

Similar cyanine dyes

    • SYBR® Green II
    • SYBR® Gold
    • YO (Oxazole Yellow)
    • TO (Thiazole Orange)
    • PG (PicoGreen)

See also

Notes and references