SYBR Gold staining of single stranded nucleic acids is strongly influenced by the presence of guanosines

SYBR Gold is one of the most strongly fluorescent members of the SYBR family of asymmetrical cyanine dyes commonly used for staining double and single-stranded DNA and RNA. The dye fluorescence increases dramatically upon nucleic acid binding. The primary mode of binding to double-stranded DNA is through intercalation between the base-paired deoxyribonucleotides, while the precise mode of binding to single-stranded DNA and to RNA is less well understood. Here we show that the fluorescence activity of SYBR Gold is strongly influenced by the presence of guanines in single-stranded nucleic acids. We expect this insight to aid in the evaluation of SYBR Gold-based measurements of nucleic acid abundance and spark further studies into the binding behaviour of the SYBR family dyes.