SYBR Green I (SG) is an asymmetrical cyanine dye[1] used as a nucleic acid stain in molecular biology.

Higher concentrations of SYBR Green can be used to stain agarose gels in order to visualise the DNA present.

[3] The study concluded that Sybr Green exhibits the highest fluorescence enhancement (AFE) and provides the best characteristic for PCR methods.

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 SYBR Green I was on the order of 30 times less mutagenic than ethidium bromide.