Characterization of SYBR Gold nucleic acid gel stain: a dye optimized for use with 300-nm ultraviolet transilluminators.

Abstract The highest sensitivity nucleic acid gel stains developed to date are optimally excited using short-wavelength ultraviolet or visible light. This is a disadvantage for laboratories equipped only with 306- or 312-nm UV transilluminators. We have developed a new unsymmetrical cyanine dye that overcomes this problem. This new dye, SYBR Gold nucleic acid gel stain, has two fluorescence excitation maxima when bound to DNA, one centered at ∼300 nm and one at ∼495 nm. We found that when used with 300-nm transillumination and Polaroid black-and-white photography, SYBR Gold stain is more sensitive than ethidium bromide, SYBR Green I stain, and SYBR Green II stain for detecting double-stranded DNA, single-stranded DNA, and RNA. SYBR Gold stain's superior sensitivity is due to the high fluorescence quantum yield of the dye–nucleic acid complexes (∼0.7), the dye's large fluorescence enhancement upon binding to nucleic acids (∼1000-fold), and its capacity to more fully penetrate gels than do the SYBR Green gel 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 subsequent molecular biology protocols.