Description
Optical properties
λ abs = 743 nm
ε max = 1.2×10 5 M -1 cm -1
λ fl = 763 nm
n fl = 10 %
τ fl = 0.6 ns
CF 260 = ε 260 /ε max = 0.07
CF 280 0 = ε 280 /ε max = 0.07
ATTO 740 together with ATTO 725 belongs to a new generation of fluorescent labels for the near infrared spectral region.
Characteristic features of the dye are strong absorption and good fluorescence as well as excellent thermal and photo-stability. ATTO 740 is a cationic dye. After coupling to a substrate the dye carries a net electrical charge of +1. ATTO 740 is a pH sensitive product. While practically stable up to pH 7.4 (PBS-buffer), it slowly degrades at higher pH. If exposed to higher pH for coupling purposes, we recommend reducing the pH immediately after completion of the reaction. The fluorescence is excited most efficiently in the range 720 - 755 nm.
