Figure 1

Spinner flask suspension cultures allow for the extended maintenance of UCX® spheroids without necrotic centres. (A) Phase contrast and fluorescence representative images of spheroids at days 3, 9 and 11. (Top) Haematoxylin and eosin (H&E) staining of UCX® spheroid sections. Scale bar = 100 μm; n = 3. (Bottom) Viability of UCX® spheroids in culture as assessed by staining with fluoresceine diacetate (FDA; live cells, green) and propidium iodide (PI; dead cells, red). Scale bar = 100 μm; n = 3. (B) Representative immunofluorescence images of UCX® spheroid cryosections labelled with Ki-67 (red) at days 3 and 11 in culture. Nuclei were labelled with DAPI (blue). Scale bar = 100 μm; n = 3. (C) Sizes of UCX® spheroids at days 2, 4, 6, 7, 9 and 11. Sizes were measured from 7 to 13 captured images of spheroids. Spheroids reached an average size of 308 ± 9.84 μm from day 4 onwards. Data are shown as mean ± standard error of the mean; n = 3. (D) Biomass quantification measured by BCA kit at days 2, 4, 6, 8, 9 and 11. Data are shown as mean ± standard deviation; n = 3. **P < 0.01; ***P < 0.001.