Atto 647 is an advanced fluorescent dye for the red spectrum, notable for its strong absorption, high fluorescence yield, stability, and water solubility. It has a net zero charge, is stable at physiological pH and up to pH 8, but degrades at higher pH. The dye is highly hydrophilic and best excited between 615 - 660 nm, with suitable sources including the He:Ne laser (633 nm), the Krypton-Ion laser (647 nm), and a 650 nm diode laser. Atto 647 is usually coupled to DNA and RNA oligonucleotides.
Figure 1. Structure of 5'-Atto 647 (R = sequence).
metabion offers Atto 647 (Figure 1) in its DNA and RNA portfolio as a 5'-, 3'- or internal Atto 647-dT modification: