143413-85-8

YODi-1 (Oxazole Yellow Homodimer, also known as YOYO^®-1) is a green fluorescent carbocyanine dimeric dye. YODi-1 is a cell-impermeant nucleic acid stain that is nonfluorescent in the absence of nucleic acids but exhibits over a thousand-fold fluorescence enhancement upon binding to dsDNA.

The bright fluorescence signal and low background make YODi-1 ideal for staining nucleic acids on microarrays, as well as for nuclear and chromosome counterstaining in multicolor fluorescence labeling experiments. YODi-1 can also be used for the analysis of single molecules of DNA.

ex/em: 491/509 nm
Extinction coefficient (ε): 98900 cm??1M??1
Quantum yield (Φ): 0.52

Thiazole orange dimer YOYO 1 is a green fluorescent dye used for DNA staining. It belongs to the monomethine cyanine dye family and is a tetracationic homodimer of oxazole yellow (abbreviated as YO, hence the name YOYO), usually provided as a tetraiodide salt. In aqueous buffer, the free YOYO-1 dye (λmax 458 nm; λmax 564 nm) has a very low fluorescence quantum yield, but after binding to double-stranded DNA through diintercalation, the fluorescence intensity is increased by 3200 times (λmax 489 nm; λmax 509 nm).

[1] Wang L, et al.Ultrafast Transient Absorption Spectra of Photoexcited YOYO-1 molecules call for additional investigations of their fluorescence quenching mechanism. J Photochem Photobiol A Chem. 2018 Dec 1;367:411-419.

490/508 nm

0.37