Leica, AD-665-25, ATTO 665 Carboxy Fluorescent Label 5 mg

Optical properties
λ abs = 662nm
ε max = 1.60×10 5 M -1 cm -1
λ fl = 680 nm
n fl = 60 %
τ fl = 2.9 ns
CF 260 = ε 260 /ε max = 0.07
CF 280 = ε 280 / ε max = 0.06
ATTO 665 is a new fluorescent label related to ATTO 647N .
Characteristic features of the label are strong absorption, extraordinarily high fluorescence quantum yield, high thermal and photo-stability, and exceptionally high stability towards atmospheric ozone. In common with most ATTO-labels, absorption and fluorescence are independent of pH, at least in the range of pH 2 to 11, used in typical applications.
ATTO 665 is a cationic dye. After coupling to a substrate the dye carries a net electrical charge of +1. ATTO 665 is a hydrophobic dye. The fluorescence is excited most efficiently in the range 640 - 675 nm . A suitable excitation source is the 647 nm line of the Krypton-Ion laser or a diode-laser emitting at 650 nm.