OG514 is the same fluorophore as Oregon Green 514 (Oregon Green® is the trademark of ThermoFisher). OG514 acid is an amine-reactive compound used for creating green, fluorescent bioconjugates. It has excitation/emission maxima approximately 489/526 nm. It is an excellent replacement for rhodamine 6G that has poor solubility in most common solvents, thus practically hard to use. Although it is a fluorescein derivative, it has significantly improved photostability and a lower pKa, making its fluorescence essentially pH insensitive in the physiological pH range.