The effect on IRP-RNA-binding activity of incubating cell lysates with either Munro buffer (control) or Munro buffer containing either 311 (10 or 25 μmol/L) or DFO (50 or 150 μmol/L) for 30 minutes at 4°C. The lysates were derived from cells pretreated for 20 hours at 37°C with either FAC (100 μg/mL) or 311 (25 μmol/L). The result is a typical experiment from two experiments performed.