Fig. 2

Viability of myocardial slices during culture at the air-liquid interface. a Heart slice viability was assessed based on mCherry fluorescence intensity and the area of calcein-stained cells for up to 5 days (d0–d5) under normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. Scale bars, 500 µm. b Slice viability was quantified by measuring the area of calcein-stained cells on both sides of the slices on days 1–5 of culture and by normalizing to the area of day 0. c Survival of CMs under normoxic and hypoxic conditions was assessed by mCherry signal intensity on both sides of the slices on days 1–5 of culture normalized to day 0. In b and c, signals of three independent experiments with two to three slices each (in total, n = 6 for normoxia, n = 9 for hypoxia) were quantified, and means and SDs (standard deviations; error bars) are given. Stars indicate significant changes with p less than 0.05. n.s. indicates not significant and n.d. indicates not detected