Two-photon
fluorescence imaging of esterase in liver cancer cells
by DCIP-R probes. (a) Representative fluorescence images
of HepG2 or HL7702 cells, which were incubated with DCIP-R1 or -R4 for 10 min, respectively; (b) quantification
of the average fluorescence intensity obtained from (a); (c) representative
fluorescence images of HepG2 pretreated with AEBSF at various concentrations
(0, 0.5, and 1 mM) for 30 min before staining with DCIP-R1; (d) quantification of average fluorescence intensity obtained from
(c); (e) fluorescence images of HepG2 cells stained with 1 μM
of DCIP-R1 (upper panel) and -R4 (lower
panel) from 0 to 30 min at 37 °C. Cell imaging was performed
by two-photon microscopy: λex = 960 nm, λem = 604–678 nm for the red channel. Scale bars: 50
μm. Data are presented as mean ± SD. Significant differences
were analyzed using the Kruskal–Wallis test with the Dunn’s
multiple comparison test. ****p < 0.0001.