Atto 647N is a new generation fluorescent dye dedicated towards the red spectral region. It is a cationic dye and carries a net electrical charge of +1 post substrate coupling reaction. Streptavidin, isolated from Streptomyces avidinii, is a tetrameric protein of 4 x 13.2 kDa which binds very tightly to the small molecule biotin. The dissociation constant of the complex is extremely small (Kd ≈ 10-15 M), ranking among the strongest non-covalent interactions. Atto streptavidin conjugates are readily soluble in water.
Atto 647N-Streptavidin is designed for application in the area of life science, e.g., labeling of DNA, RNA or proteins. Atto streptavidin conjugates may be used as secondary detection reagents in flow cytometry, immunoassays, blot analysis, and histochemical applications. Atto 647N -Streptavidin is suitable for multiplex analysis, including multicolor imaging.