Leica, AD678H35, ATTO 678H NHS-Ester Hydrophilic Fluorescent Label 5 mg

Optical properties
λ abs = 678 nm
ε max = 1.5×10 5 M -1 cm -1
λ fl = 708 nm
n fl = 20 %
τ fl = 1.5 ns
CF 260 = ε 260 /ε max = 0.12
CF 280 = ε 280 / ε max = 0.08
Like ATTO 643 and ATTO 647N, ATTO 678H belongs to a new generation of long-wavelength fluorescent markers. The dye's characteristic properties include strong absorption, good fluorescence quantum yield, and high thermal and photochemical stability. ATTO 678H is highly hydrophilic and highly water-soluble, and compared to ATTO 680, it exhibits significantly reduced aggregation behavior and a low tendency toward nonspecific binding. After coupling to a substrate, the dye is singly negatively charged. Unlike ATTO 680, it is not an electron acceptor; its fluorescence is not quenched by guanine, tryptophan, etc. Efficient fluorescence excitation occurs in the 665–695 nm range.