Extended Data Fig. 2: In vitro and in vivo characterization of the HS-169 probe uptake.

a, Spectrofluorometric measurements show emission peak of HS-169 in the concentration range varying from 0 to 120 µM and 200 nM Aβ₄₂ fibril (incubation time 10 min); Data are shown as mean ± SD; Repetition n = 3. b, Fluorescence intensity of HS-169 (60 µM) and Aβ₄₂ fibrils in the concentration range varying from 0 to 200 nM. c, Linear relation between Aβ₄₂ fibril concentration and fluorescence intensity was observed, Data are presented as mean ± SD. Repetition n = 3. d–g, Comparison of Aβ load at 2 h and 24 h post-injection of the HS-169 probe in arcAβ mouse. (d) LMI images acquired at 2 h time point post-injection of HS-169 in a 22-month arcAβ mouse (d). LMI images acquired at 24 h post-injection of HS-169 in a 22-month arcAβ mouse with the same dose (e). Contrast-to-noise ratio (CNR) comparison between LMI and widefield (WF) fluorescence images acquired at 2 h and 24 h post-injection of HS-169 in one mouse brain (f,g). The CNR was calculated via (sig - bg)/noise; where sig and bg are the mean fluorescence intensities in ROIs as indicated in d and e; noise was calculated as the standard deviation in the ROI in a background region. Both image pattern and the CNR values of the LMI images acquired at these two time points are comparable, while there is a reduction in the CNR values in the WF image at 24 h compared to 2 h post-injection. Data is presented as mean ± SD (analysis of the 6 ROIs over one mouse brain).