Supplementary Material for: Single-cell ionic current phenotyping explains stem cell-derived cardiomyocyte action potential morphology

This is supplementary figures for the manuscript titled: "Single-cell ionic current phenotyping explains stem cell-derived cardiomyocyte action potential morphology"

The manuscript describes the use of a novel voltage clamp protocol that can be used to describe the ionic current phenotype of stem cell derived cardiomyocytes. Within the manuscript, we describe how the protocol was used to draw the following conclusions about the cardiomyocytes used in this study:

• L-type calcium current (ICaL) drives upstroke in iPSC-CMs with a depolarized AP morphology.
• Rapid delayed rectifier K+ current (IKr) plays a role in establishing the maximal diastolic potential.
• Seal-leak current contaminates VC recordings and contributes to a depolarized maximal diastolic potential.
• Large positive currents present at potentials >40 mV correlate with a shortened AP duration.
• Several cells contain a strong outward current at 6 mV that is not present in computational AP models and
correlates with AP duration