Marina Blue is a proprietary dye manufactured by Life Tech/ThermoFisher, it is available as a fluorescent dye that can be conjugated to an oligo, either RNA or DNA. This is a post synthesis conjugation to a primary amino group. The amino group can be placed at the 5' and 3' and for internal positions an amino modified base is used, e.g Amino dT C6
The amine-reactive Marina Blue® succinimidyl ester can be used to create blue-fluorescent bioconjugates. Based on the 6,8-difluoro-7-hydroxycoumarin fluorophore, Marina Blue® dye exhibits bright blue fluorescence emission near 460 nm and is optimally excited by the intense 365 nm spectra line of the mercury-arc lamp. Because the pKa values of Marina Blue® derivatives are 2-3 log units lower than those of the corresponding 7-hydroxycoumarin conjugates, Marina Blue® conjugates are strongly fluorescent even at neutral pH.