Figure 2: The optimal concentration ratio of ZZC and R8 for labeling ASCs.

(a–d) The phase and (e–h) fluorescence images of ASCs labeled with ZZC (250 nM) and various concentrations (0, 2.5, 25, 250 μM) of R8 complexes. (i–l) A flow cytometry analysis of the labeling efficiency and fluorescence intensity. (m) Graphs of the labeling efficiency and (n) fluorescence intensity of ASCs labeled with ZZC (250 nM) and various concentrations (0, 2.5, 25, 250 μM) of R8 complexes as determined flow cytometry. (o–q) A flow cytometry analysis of the labeling efficiency and fluorescence intensity of ASCs labeled with the optimal concentration ratio of ZZC (250 nM) and R8 (250 μM) under various transduction times. (r–u) Confocal microscopy images of R8-ZZC-labeled ASCs ((r) phase contrast of ASCs, (s) the red fluorescence of ZZC, (t) the blue fluorescence of a nucleus stained with Hoechst33342, and (u) a merged image).