Fig. 1

Viability and metabolic activity after long-term cold storage. After preparation, hPCLS were cold stored in DMEM/F-12, TiProtec, or TiProtec (-), at 4 °C for up to 28 days. A) Viability changes were assessed by Calcein AM and EthD-1 staining. Viability is expressed as a percentage of the baseline viability of freshly sliced hPCLS at day 0 (100%). A positive control was also measured, after treating hPCLS with 1% Triton-X. Data set was analyzed using a RM two-way ANOVA followed by a Tukey´s multiple comparison test: * simple effects of the medium and # simple effects of storage time. Data are presented as means ± SEM (n = 4 patients, single dots represent average activity from 3 technical replicates per patient). Asterisks indicate significant differences (** p < 0.01, # p < 0.05, ## p < 0.01). B) Representative images of Live/Dead™ staining of hPCLS at baseline (T0) and after long-term cold storage. C) Quantification of Alamar Blue assay. The baseline metabolic activity was measured on day 0 and set as 100%. A negative control with only medium was also included. Metabolic activity changes are presented as a percentage of the baseline activity of freshly cut hPCLS (T0). Data set was analyzed using a Mixed-effects model followed by a Tukey´s multiple comparison test: * simple effects of the medium and # simple effects of storage time. Data are presented as means ± SEM (n = 4–6 patients, single dots represent averaged activity from 3 technical replicates per patient). Asterisks indicate significant differences (*p < 0.05, # p < 0.05, ## p < 0.01, ### p < 0.001)