Characterization of SYBR gold nucleic acid gel stain: A dye optimized for use with 300-nm ultraviolet transilluminators

The highest sensitivity nucleic acid gel stains developed to date are optim ally excited using short-wavelength ultraviolet or visible light, This is a disadvantage for laboratories equipped only with 306- or 312-nm UV transil luminators. We have developed a new unsymmetrical cyanine dye that overcome s this problem. This new dye, SYBR Gold nucleic acid gel stain, has two flu orescence excitation maxima when bound to DNA, one centered at similar to 3 00 nm and one at similar to 495 nm. We found that when used with 300-nm tra nsillumination and Polaroid black-and-white photography, SYBR Gold stain is more sensitive than ethidium bromide, SYBR Green I stain, and SYBR Green I I stain for detecting double-stranded DNA, single-stranded DNA, and RNA. SY BR Gold stain's superior sensitivity is due td the high fluorescence quantu m yield of the dye-nucleic acid complexes (similar to 0.7), the dye's large fluorescence enhancement upon binding to nucleic acids (similar to 1000-fo ld), and its capacity to more fully penetrate gels than do the SYBR Green g el stains. We found that SYBR Gold stain is as sensitive as silver staining for detecting DNA-with a single-step staining procedure. Finally, we found that staining nucleic acids with SYBR Gold stain does not interfere with s ubsequent molecular biology protocols. (C) 1999 Academic Press.