Fig. 3

C2 fusion proteins label apoptotic Neuro2a cells in vitro. a, c Confocal images of control (CTRL) and apoptotic (STAU, treated with 3 µM staurosporine) Neuro2a cells labelled with either C2-mKate or C2-SNAP or their mutated counterparts C2m2-mKate and C2m2-SNAP; scale bar 10 µm. b, d Quantification of mKate or SNAP-tag fluorescence intensity on Neuro2a cells with or without staurosporine treatment. e Confocal images of control (CTRL) or apoptotic (STAU, treated with 3 µM staurosporine) Neuro2a cells labelled with PSVue. f Quantification of PSVue fluorescence intensity on Neuro2a cells with or without staurosporine treatment. g Comparative signal strength of mKate, SNAP and PSVue on apoptotic Neuro2 cells. Data presented as means ± standard error of the mean (b, d, f) or geometrical means ± 95% confidence intervals (g) (n = 20–30 images per biological replicate, 3 independent biological replicates). Means were compared by one-way ANOVA and post-hoc Tukey test (b, d, f) or by Kruskal–Wallis one-way analysis of variance and post-hoc Dunn’s test (g). p values < 0.05 were considered as significant. RFU relative fluorescence units