Fig. 2.
Effect of spermidine on proliferation and IgM productivity of HB4C5 cells. HB4C5 cells were inoculated at 1 × 105 cells/mL in ITES-ERDF medium supplemented with or without 4.5 mM spermidine and cultured for 5 days. Section (a) shows the growth curves of HB4C5 cells in spermidine-supplemented ITES-ERDF medium (○) and that in ITES-ERDF medium (●). Viable cell density was determined using hemocytometer after trypan blue staining. Section (b) indicates IgM productivity calculated by the formula mentioned in Materials and methods section. The white and black bars express IgM productivity of HB4C5 cells in spermidine-supplemented medium and control medium, respectively. Results are expressed as the mean ± SD of two independent measurements