Unlocking the ultrastructure of colorectal cancer cells in vitro using selective staining

Figure 4 Undifferentiated heterogenous population of SW480 cells. A-D: SW480 cells grown on membrane filters and examined day 1 post-confluency. A: Simple squamous (left) and simple cuboidal (right) distinctions are already evident in cells on day 1 post-confluency. Cells exhibit vacuoles (v), microvilli (m), and invasive processes (inv) are evident projecting into filter pores; B: Large population of mitochondria (mit) are evident which exhibit branching characteristics; C: Intercellular junctions (black arrow) exhibit early formation of the tight junction (white arrow). Mitochondria (mit) with numerous cristae are present; D: Simple squamous cells exhibiting long invasive processes (inv) into the filter pores. Mitochondria (mit); E-H: SW480 cells grown on membrane filters and examined day 12 post-confluency. E: Cells remain a monolayer with microvillar (m) projections and abundant mitochondria (mit); F: Junction between two adjoining cells growing on membrane (mem) showing no intercellular spaces, tight junction formation (white arrow), abundant mitochondria (mit), and glycogen (gl) stores; G: High power micrograph depicting the glycogen (gl) granules in the cytoplasm in amongst mitochondria (mit); H: Basolateral region of cell body (cb) showing deep invasive processes (inv) projecting into filter pores (p). These processes extend to depths of approximately 10 μm and cellular organelles such as mitochondria (mit) are present in these processes, showing deep anchorage of cell.