Effect of inducing erythroid differentiation by DMSO in Friend 707 cells on the mRNA levels of

frataxin (Frda),β-globin, and β-actin(loading control). Northern blot analysis was performed by extracting total mRNA from cells incubated in the presence (+) or absence (−) of 1.5% DMSO for 120 hours at 37°C. The isolated RNA was electrophoresed on a 1.2% formaldehyde gel, transferred to nylon membrane, and sequentially probed under high stringency conditions (see “Materials and methods” for details). (A) Ethidium bromide staining of the agarose gel; (B) Frda; (C) β-globin; and (D) 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 5 experiments performed.