SYBR Safe

SYBR Safe is a cyanine dye^[1] used as a nucleic acid stain in molecular biology.^[2] SYBR Safe is one of a number of SYBR dyes made by the Life Technologies Corporation. SYBR Safe binds to DNA. The resulting DNA-dye-complex absorbs blue light (λ_max = 509 nm) and emits green light (λ_max = 524 nm).

SYBR Safe

Names
IUPAC name (Z)-4-((3-Methylbenzo[d]thiazol-2(3H)-ylidene)methyl)-1-propylquinolin-1-ium 4-methylbenzenesulfonate
Identifiers
CAS Number	1030826-36-8 Y
3D model (JSmol)	Interactive image
InChI InChI=1S/C21H21N2S.C7H8O3S/c1-3-13-23-14-12-16(17-8-4-5-9-18(17)23)15-21-22(2)19-10-6-7-11-20(19)24-21;1-6-2-4-7(5-3-6)11(8,9)10/h4-12,14-15H,3,13H2,1-2H3;2-5H,1H3,(H,8,9,10)/q+1;/p-1 Key: YTHKVAWQFBVEJQ-UHFFFAOYSA-M
SMILES CCC[n+]1ccc(C=C2Sc3ccccc3N2C)c2ccccc21.Cc1ccc(S(=O)(=O)[O-])cc1
Properties
Chemical formula	C28H28N2O3S2
Molar mass	504.66 g·mol−1
Solubility	Soluble in dimethylsulfoxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

A comprehensive study of Thiazole-Orange-Based DNA Dyes was published, involving SYBR Safe, SYBR Green, PicoGreen, SYTO-16, SYTO-9 and a new derivative TOPhBu. Here, the synthesis of these compounds are published and characterised spectroscopically to quantify their fluorescence enhancement upon binding to double-stranded DNA. The ability of the dyes to detect DNA at low concentrations was evaluated using two new metrics, absolute fluorescence enhancement (AFE) and relativefluorescence enhancement (RFE). They were tested in qPCR experiments showing some important differences in the sensitivity and qPCR efficiency, which facilitates the DNA marker selection for analytical purposes. ^[3]

Safety

SYBR Safe is marketed as a safer alternative to ethidium bromide.^[4] SYBR Safe has a very similar structure to thiazole orange,^[5][6][7] which has a methyl group attached to the charged nitrogen, whereas SYBR Safe has an N-propyl group. Thiazole Orange has been shown to be three to four times less mutagenic than ethidium bromide whereas SYBR Safe is four to five times less mutagenic.^[8] Additionally, according to the Life Technologies website, SYBR Safe is not lethal in rats at doses as high as 5 g/kg, and rats don't show symptoms of acute toxicity. Thiazole orange does show toxicity at this dose.

Similar cyanine dyes

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

See also

• GelGreen - competing product with a different molecular structure and size