Before a new antimicrobial wound spray can be approved for clinical trials, its toxicity must be evaluated on cultured human dermal fibroblasts.
Cultured fibroblasts were seeded into four identical culture wells. Sterile phosphate-buffered saline (PBS) was added to the first well as a control, and a different candidate formulation of the antimicrobial spray was added to each of the remaining three wells.
The fibroblasts were incubated for 6 hours6\text{ hours}6 hours, after which the percentage of viable cells was determined.
Table 1 shows the results.
Table 1
| Substance added to dermal fibroblasts | Percentage of viable cells after 6 hours6\text{ hours}6 hours (%) |
|---|---|
| Sterile PBS (control) | 95 |
| Formulation Alpha | 94 |
| Formulation Beta | 96 |
| Formulation Gamma | 95 |
Explain the conclusion that can be made from this data.
