The effect of incubation time with DMSO on the mRNA levels of

frataxin (Frda),transferrin receptor (TfR),Nramp2, β-globin, orβ-actin in Friend 707 cells. Total mRNA was extracted from cells incubated in the presence (+) or absence (−) of 1.5% DMSO for 0 to 120 hours at 37°C. Northern blot analysis was performed as described in Figure 2. (A) Ethidium bromide staining of the agarose gel, (B) Frda, (C) TfR, (D) Nramp2, (E) β-globin, and (F) β-actin. Densitometric analysis of the results normalized to the β-actin loading control are shown to the right of each relevant blot. The result illustrated is a typical experiment from 3 experiments performed.