Ricin a chain

Full materials and method has been included as supplementary information. Briefly, cell culturing, immunocytochemistry, cytotoxicity assays, western immunoblotting, flow cytometry, and confocal microscopy was performed as described elsewhere [Arsenault et al., 2014 (link)]. Transfection of Neuro2A cells was performed as manufacturer recommends using pDNA vectors described elsewhere [Bajohrs et al., 2004 (link)]. Peptides and proteins used in this study were described previously [Arsenault et al., 2013 (link); Arsenault et al., 2014 (link)]. Annexin V-FITC and Ricin A chain were obtained from Sigma-Aldrich (Dorset, UK).

Cardiac organoids in hydrogel were given fresh CMM alone, or with one of a panel of well-studied compounds for stimulating increased heart rates or inducing decreases in heart rates. Specifically, the organoids were subjected to CMM alone, 100 μM isoproterenol (Sigma-Aldrich, St. Louis, MO, USA) for 30 min, 500 nM epinephrine (Sigma-Aldrich) for 15 min, 1 μM quinidine (Sigma-Aldrich) for 10 min, 100 nM astemizole (Sigma-Aldrich) for 30 min, or 100 nM ricin A chain (Sigma-Aldrich) for 30 min. Following each of these incubation periods, video files were captured using a Leica inverted microscope under brightfield. The resulting video file was then processed into digitized representations of moving pixels, after which the sum of moving pixels was plotted versus time. 10-s segments of these videos were employed for the visual plots presented in the Results.