Hepcidin expression in liver and spleen of mice infected with GAS and iron staining. (A) Immunohistochemistry using anti-mouse hepcidin antibodies on livers and spleens of mice challenged with group A Streptococcus (GAS), magnification × 50 (spleen) and × 400 (liver). (B) Iron staining of splenic sections by Perl blue method following similar mouse challenge.