iCell Cardiomyocytes also show sensitivity to known cardiotoxic compounds affecting biochemical processes (Figure 2). Cardiomyocytes were exposed to a diverse set of compounds known to have adverse effects on cardiomyocytes over a broad range of EC50 values. Cell viability was subsequently assessed via CellTiter Glo (data courtesy of Chad Zimprich, Promega) and demonstrated an expected sensitivity.
Cell handling plays a critical role in cell-based assay investigations. iCell Cardiomyocytes, like terminally differentiated native cardiomyocytes, do not divide in culture. Thus, mistakes in plating cannot be undone by simply waiting for the cells to divide and/or splitting and replating. Therefore, cell viability upon thaw from cryopreservation and the plating efficiency, i.e., the ratio of cells added (seeded) into a well over the actual number of cells that attach to the bottom of the well, must be taken into consideration when setting up experiments.
In the case of iCell Cardiomyocytes, an investigator can either use these two metrics, which are part of the QC program, as supplied by CDI, or they can determine cell viability on their own and combine that result with the supplied QC plating efficiency to determine the appropriate number of cells to place in each well.