Thiazole orange dimer YOYO 1

Thiazole orange dimer YOYO-1 is a green fluorescent dye used for DNA staining. It is a tetracationic homodimer of oxazole yellow (YO) and is typically provided as a tetraiodide salt. In aqueous buffer, the free YOYO-1 dye (?max 458 nm; ?max 564 nm) exhibits low fluorescence quantum yield, but upon binding to double-stranded DNA through diintercalation, its fluorescence intensity increases by 3200 times (?max 489 nm; ?max 509 nm) .