The effect of incubation with DMSO on the mRNA levels of

frataxin (Frda) and β-actin(loading control) in mouse LMTK⁻ fibroblasts and the RAW264.7 macrophage cell line. Northern blot analysis was performed as described in Figure 2 using total mRNA extracted from cells after a 120-hour incubation at 37°C in the presence (+) or absence (−) of 1.5% DMSO. (A) Ethidium bromide staining of the agarose gel, (B) Frda, and (C) β-actin. The result illustrated is a typical experiment from 3 experiments performed.