What are the most popular green DNA dyes?

SYBR Green, SYBR Safe, and Eva Green are the three most popular green DNA dyes.

SYBR Green

SYBR Green is a green fluorescent cyanine dye that absorbs at a wavelength around 497 nm and emits fluorescence around 520 nm. It has a high affinity for double-stranded DNA but will also fluoresce with single-stranded DNA and RNA, although with less intensity. It binds to DNA through a combination of DNA intercalation and external binding.

SYBR Safe

Specifically formulated to be a less hazardous alternative to Ethidium Bromide, SYBR Safe is a safe and highly sensitive fluorescent DNA stain for visualizing DNA in agarose or acrylamide gels. It binds to the DNA double helix. Any SYBR Safe that is bound to DNA fluoresces a bright green color with UV or blue light excitation.

Eva Green

Eva Green is a green dye that is almost non-fluorescent on its own but becomes highly fluorescent on binding to double-stranded DNA. It is very stable at high temperatures and has extremely low to no mutagenicity or cytotoxicity. Eva Green inhibits Polymerase Chain Reaction (PCR) to a lesser extent than other dyes, making it the preferred option for applications such as quantitative real-time PCR.

YOYO-1/DiYO-1/TOTO-1/DiTO-1

These are a family of cyanine dyes. YOYO-1 (and its chemical equivalent, DiYO-1) has a maximum emission of 509 nm. It is non-fluorescent in the absence of nucleic acids, and generates a very bright fluorescence signal upon binding to DNA. TOTO-1 (and its chemical equivalent, DiTO-1) has a maximum emission of 535 nm. This family of DNA probes is particularly well known for its high affinity for DNA. Upon binding to DNA, these probes can experience a one-thousand-to-three-thousand-fold increase in fluorescence. This strong affinity for DNA makes them excellent for experiments which require great sensitivity. They are well suited for staining fixed or dead cells. In this regard, these probes have been commonly used in cell viability and cytotoxicity assays in conjunction with platforms such as flow cytometry.