Figure 4
Spectroscopic characterization of FlAsH. (a) Emission spectra of free FlAsH-EDT2 (red) and purified FlAsH-FCMybbR (green); the vertical dashed lines and arrow illustrate the 16 ± 1 nm redshift of the emission peak upon labelling. (b) Fluorescence decay data of free FlAsH-EDT2 and (c) FlAsH-FCMybbR. (d) Fluorescence anisotropy decay of free FlAsH-EDT2 (dashed line) compared to FlAsH-FCMybbR (yellow). Solid black lines in (b–d) are fitted exponential decays according to equations (1,3). FCS data for (e) FlAsH-EDT2 (yellow), (f) AF488 (green), and (g) FlAsH-EDT2 in the presence of 20 mM cysteamine, 2 mM Trolox (yellow). (h) purified FlAsH-FCMybbR in the same conditions as (g). All FCS curves were normalized at 10−6 s for comparison purposes. Solid lines in (e–h) are the fitted FCS curves according to equation (4). The lifetime, anisotropy decay and FCS fitting parameters are summarized in Supplementary Tables S1 and S2.
