Leica, AD-620-61, ATTO 620 Streptavidin Fluorescent Label 1 mg

Optical properties
λ abs = 620 nm
ε max = 1.2×10 5 M -1 cm -1
λ fl = 642 nm
n fl = 50 %
τ fl = 2.9 ns
CF 260 = ε 260 /ε max = 0.04
CF 280 = ε 280 / ε max = 0.06
ATTO 620 belongs to a new generation of fluorescent labels for the red spectral region. Characteristic features of the label are strong absorption, temperature dependent fluorescence, and high thermal and photo-stability.
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 620 is a cationic dye. After coupling to a substrate the label carries a net electrical charge of +1
The label is moderately hydrophilic. Its fluorescence is excited most efficiently in the range 600 - 630 nm.