Figure 3
Impact of drug storage, evaporation, and DMSO concentration on cell viability in breast cancer cell lines. (a) HCC38 breast cancer cells were treated with 2–1024 µM carboplatin (for 24 hours) that had been stored at 4 °C (fridge) or −20 °C (freezer thawed daily). (b) Standard PCR plates (sealed with aluminum tape) were shown to result in less evaporation of pharmaceutical drugs during storage. Wilcoxon test was used to calculate statistical significance (Benjamini-Hochberg adjusted p-values). ns = not significant (P > 0.05); *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001. (c) The perimeter wells of flat-bottom culture microplates exhibited higher resazurin-based absorbance values than wells in the middle of the plate, indicating less evaporation in the middle wells. Wilcoxon test was used to calculate statistical significance (Benjamini-Hochberg adjusted p-values). ns = not significant (P > 0.05); *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001. (d) MCF7 breast cancer cells were treated with 0.33–10% (v/v) DMSO for 24 hours. Cell viability was determined using the resazurin reduction assay with 10% resazurin solution incubated for four hours. Error bars depict the standard error of the mean. The dose-response curves and bar plots were generated using ggplot2 (version 3.2.1) in R51.
