Human iPSC-Derived Cardiac Cells
Frequently Asked Questions
 
How pure are the cardiomyocytes (i-HCm) in this cell preparation?
We provide cellular preparations containing at least 40% i-HCm, identified by cardiac troponin staining in flow cytometry.
 
What is the advantage of non-purified cardiomyocytes?
As with all organs in the human body, the heart is comprised of multiple cell types. Typically, the human heart contains 30-40% cardiomyocytes, as well as cardiac fibroblasts, endothelial cells and smooth muscle cells. Preparations with these relevant cell types offer more physiologically relevant research models, and better support cardiomyocyte maturity, health and function1-3. Since they are not genetically engineered to select only for cardiomyocytes, our non-engineered iPSC don’t integrate genetic selection cassettes and thus present no genotoxic risks.
 
Is it normal for iPSC-Derived Cardiac Cell culture to visually change over time, including the growth of non-iHCm cells?
Cardiomyocytes are terminally differentiated and non-proliferative.  In contrast, fibroblasts, endothelial cells and others proliferate, increasing in number more prominently as the culture term progresses
 
What affects the beating behavior of i-HCm?
The physiology of i-HCm depends highly on cell density, health, temperature, pH and medium nutrients. Seeding density that is inadequate for proper cell connections to form can compromise cell health and result in asynchronous beating. Further, i-HCm may display abnormal, slow, or arrested beating if media change schedules are altered or cells are left outside the incubator over 5 minutes.  Nonetheless, cardiomyocytes are fairly hardy, and usually resume normalized beating behavior after 30 minutes re-incubation at 37°C in fresh medium. Prior to measurement in a physiological assay device, allow i-HCm to adjust and stabilize 5-30 min after moving them from the incubator.
 
Can I passage the iPSC-Derived Cardiac Cells?
Human iPSC-Derived Cardiomyocytes are highly specialized, sensitive, terminally differentiated, non-dividing cells that cannot be subcultured.  However, it is possible to enzymatically dissociate and remove i-HCm from culture vessels for downstream applications like flow cytometry. 
 
Can I use extracellular matrices other than GFRm?
We recommend coating laminin at a concentration of 10 ug/cm2 onto UV-light activated glass, since GFRm binds poorly to this substrate.  Otherwise, GFRm constitutes a satisfactory ECM for coating plastic culture vessels and plating cardiomyocytes.
 
Can antibiotics be used in the culture?
Penicillin/Streptomycin, or combinations of these antibiotics with the addition of Fungizone or Amphotericin, can be used in media for cells at increased risk of contamination due to long-term culture.  For sensitive electrophysiology applications like patch clamping, avoid antibiotics, which can inhibit the activity of key cardiomyocyte ion channels.
 
References
  1. Passier, R., V. Orlova and C. Mummery. 2016. Complex Tissue and Disease Modeling using hiPSCs. Cell Stem Cell, 18:309-321.
  2. Moretti, A., K. Laugwitz, T. Dorn, D. Sinnecker and C. Mummery C. Pluripotent stem cell models of human heart disease. 2013. Cold Spring Harb Perspect Med, 3 (11).
  3. Burridge P., S. Metzler, K. Nakayama, O. Abilez, C. Simmons, M. Bruce, Y. Matsuura, P. Kim, J. Wu, M. Butte, N. Huang and P. 2014. Multi-cellular interactions sustain long-term contractility of human pluripotent stem cell-derived cardiomyocytes. Am J Transl Res, 22:724-35.