(a)
(b)
(c)
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(e)
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(g)
Figure 4: Impact of different seeding aCF densities on action potential recordings of cocultures with ESC-CMs. Representative AP waveforms of cocultures with a lower (1 : 20) (a) and higher (1 : 5) (b) seeding number of aCFs. Percentage of ESC-CMs and aCFs in hanging drops cocultured for two days (c). Pictures of cocultures with aCF seeding ratios 1 : 20 (d) and 1 : 5 (e) after two days in culture. Higher number of aCFs in cocultures resulted in a decreased maximal upstroke velocity () (f) as well as a prolonged APD50 (g). Data are expressed as mean ± SEM; ; .