Immunohistochemistry of muscle biopsy. Immunohistochemistry was performed on serial paraffin sections. Sections were immersed in citrate buffer, heated in a microwave for antigen retrieval, and immunostained with antibodies against p62/SQSTM1 (1:2000; Progen) (A) and TAR-DNA binding protein-43 (1:500; Protein Tech Group) (B) according to standard procedures. The immunostaining was visualized with diaminobenzidine tetrahydrochloride and counterstained with methylene blue. Arrow indicates p62 immuno-positive aggregates within rimmed vacuoles. Some nuclei are normally immunostained with TDP-43.