Figure 1

Experimental standard calibration curve for the iron-to-ferritin ratio as a function of the fraction collected in a sucrose gradient. Experimental standard calibration curve for the iron-to-ferritin ratio as a function of the fraction collected in a sucrose gradient. Horse spleen apoferritin was loaded with different amounts of iron [44], centrifuged and loaded into a sucrose gradient (1-25%). Fractions were collected and ferritin content was determined by the BCA assay. Circles correspond to experimental data points and the calibration curve is shown as a dashed line.