4.1. H9c2 Embryonic Cardiomyocyte Cell Lines

H9c2 embryonic cardiomyocyte (Lonza) cell sub-clones, derived from the parental clone cell line embryonic BD1X rat heart tissue was used in this study. The H9c2 cardiomyocyte cell line has widely been utilised for cardiotoxicity studies for the analysis of morphological characteristics, as changes in cellular activity resemble immature embryonic cardiomyocytes with many signalling pathways conserved for their differentiation into mature myocardial cells. Furthermore, the H9c2 cardiomyocyte cell line has commonly been used in various studies relating to drug toxicity pathways (American Type Culture Collection (ATCC)) and to this end provided a viable in vitro model [63]. Cells were either sub-cultured into 75 cm² sterile flasks at the required culture ratio of either 1:5 or 1:10 or seeded at adequate densities into six-well or 96-well tissue culture plates. Initial cell starting passage was between four and six, with all experiments performed between passages 8–12.