Materials and Methods
The cell lines Sp2/0 hybridoma, HT-1080 fibrosarcoma cells, and normal dermal fibroblasts used in this study were obtained from ATCC. Hybridoma and dermal fibroblasts were cultured in DMEM/F12 + GlutaMax + 10% FBS and HT-1080 cells were maintained in EMEM + 2mM L-Glutamine + 10% FBS, respectively.
To initiate the variable serum conditions, adherent cells were detached from the growth surface using 0.25% trypsin. All cells were pelleted and resuspended in basal medium and inoculated in the reduced serum medias +/- Zap-SR in duplicate at passage 1 as indicated by Table 1. Cells were subcultured for 72 to 96 hrs and subsequently harvested in the same medium cells were propagated in. Cells were inoculated for the subsequent passage and this process was repeated for 4 passages to generate a total of 8 replicates per condition. Doubling times were calculated for each condition after each subculture and were subsequently averaged to generate the graphic data presented in Figure 1.
|Cell Line||FBS Concentration||mL Reagent/100 mL Complete Medium|
Table 1. FBS and Zap-SR Concentrations
Results and Discussion
alt: Zap-SR effectively restores cell doubling time in each cell system. Sp2/0 hybridoma cells exhibited a signficant slowing of cell proliferation when serum is reduced to .1%. Doubling time is restored with supplementation of Zap-SR. Similary, a reduction of serum to 5% in dermal fibroblasts significantly slows cell proliferation that can be restored with Zap-SR supplementation in addition to 5% serum. HT-1080 cells are sensitive to an 80% reduction in serum concentration that can prevented with the addition of Zap-SR.
Figure 1. Zap-SR restores cell doubling time in the presence of reduced serum.
Table 2 demonstrates the cost of 1 liter of 10% FBS-containing medium versus the reduced serum medium supplemented with Zap-SR. The percentage of saved cost is proportional to the amount of serum that can be removed from the culture, as Sp2/0 (.1% FBS) exhibits the largest cost savings while dermal fibroblasts (5% FBS) show savings that are less pronounced. However, all 3 cell lines demonstrate significant cost savings of the reduced serum medium supplemented with Zap-SR versus the 10% FBS-containing control medium.
|Growth Medium||Cost per Liter Growth Medium|
|10% FBS Growth Medium||$88||$91||$90|
|Reduced FBS + Zap-SR||$56||$65||$72|
|Percent Cost Savings per Liter Growth Medium||37||29||20|
Table 2. Relative cost savings of Zap-SR-containing growth medium.
The results indicate that fetal bovine serum concentrations can be lowered in multiple cell systems if the cell culture medium is proportionally supplemented with the Zap-SR product without adversely affecting cell growth. Further, inclusion of Zap-SR can reduce the overall cost of the growth medium.