TSQ-stabilized
indicators prevent unwanted physiological disruption
in human induced pluripotent stem-cell derived cardiomyocytes (hiPSC-CMs).
Plot of relative fluorescence vs time for unpaced hiPSC-CMs loaded
with 1 μM of either (a) 1 alone (black), (b) 1 + COT (exogenously added, 1 μM), or (c) 1-COT. Recordings are single trials and are bleach corrected using
an asymmetric least-squares fit. (d) Plot of normalized action potential
duration (APD) vs time in spontaneously beating hiPSC-CMs loaded with 1 alone (black) or 1-COT (green) and illuminated
continuously for the indicated time. At 1 min intervals, a 20 s movie
was acquired, and the action potential duration was assessed. Data
are mean ± SEM for n = 3 separate experiments.
Example optically recorded action potentials for (e) 1 alone (black/gray) or (f) 1-COT (black/green) at t = 0 min (black) and at t = 5 min (gray
or green) of continuous illumination. AP traces are the average of
21 and 24 aligned APs for 1 alone (black/gray) and 1-COT (black/green), respectively.