Diminished iron staining and ferritin expression in the spleen of IRP2-deficient mice. (A) The spleen from 10-week +/+ and -/- males was analyzed by Prussian Blue staining (top panels) or staining with an anti-ferritin L-chain antibody (bottom panels). Prussian blue coloration was counterstained with Nuclear Fast Red and ferritin immunostaining with hematoxylin. Pictures were acquired on a Axiophot microscope (Zeiss) with a × 20 objective. Ferritin H-chain expression was below the detection limit and is not shown. (B) IRP2 and ferritin H- and L-chain expression was analyzed in groups of 4 +/+, +/-, and -/- mice by Western (top panels) and Northern (bottom panels) blotting from 40 μg total protein or 10 μg total RNA, respectively, using β-actin as a standard. The histogram represents the level of ferritin expression after normalization for β-actin. Error bars indicate standard deviation.