ell shape and morphology were used as one means of assessing cell health and function. When mouse/rat myocytes were 24 hours after plating (Day 1), the seeded cells quickly began to flatten from their initial round shape and show formation of short, outstretched pseudopodia (Figure 3A). After Day 3, the cardiomyocytes isolated from both mouse and rat hearts looked elongated and their pseudopodia grew across each other to form a confluent monolayer culture (Figure 3A and B)