Ad Blocker Detected
Our website is made possible by displaying online advertisements to our visitors. Please consider supporting us by disabling your ad blocker.
Nucleic acid staining dyes are the fluorescent compounds that bind to the nucleic acid; DNA and RNA and help us visualize the nucleic acid in the gel after electrophoresis. Ethidium bromide is one of the oldest known nucleic acid staining dyes available nowadays.
Ethidium bromide (or EtBr) is a fluorescent dye that can be used to stain nucleic acids in molecular biology laboratories. It is an intercalating (getting inserted in between the two strands) agent that intercalates the nucleic acid. Even single-stranded RNA can be detected because it folds back to form local base pairings. The formation of local base pairings in single-stranded RANprovidess sites for the dye to intercalate.
Ethidium bromide can either be incorporated into the agarose gel during the preparation of the gel by adding an appropriate amount of EtBr solution into the gel (precast) or it can be done after running the agarose gel (post electrophoresis staining). After electrophoresis, the gel can also be stained by placing the gel in EtBr solution followed by destaining in water. It absorbs the UV irradiation at 210 nm and 285 nm and after excitation, it emits the visible light at 605 nm (orange light).
However, it is highly mutagenic and should be handled with extra care. As it is a hydrophobic molecule it can easily pass through the biological membrane (cell membrane and nuclear membrane) and gets inserted into the double-stranded DNA thereby affecting the DNA replication and transcription. To substitute EtBr, scientists have developed various other types of dyes that are less toxic but more sensitive than EtBr. These newly developed nucleic acid staining dyes are SYBR® dyes and GelRed/GelGreen dyes.
SYBR® Safe is a member of SYBR® dyes developed by Life Technologies Corporation. It is a cyanine dye that has a structure similar to that of the Ethidium bromide and is 4 to 5 times less toxic than EtBr. The nucleic acid detection sensitivity of SYBR® Safe stain is comparable to that of the EtBr. It has been classified as a non-toxic, non-hazardous waste under the U.S. Federal regulation.