TDP-43 Immunohistochemistry in Human Frontal Cortex

As described previously [29 (link)], paraffin-embedded human brain sections of 5 μm from the frontal cortical lobe were examined to evaluate reactivity towards TDP-43 protein. The paraffin-embedded sections were deparaffinized in xylene and rehydrated in a descending series of ethanol. Endogenous peroxidases were blocked with 5% hydrogen peroxide in methanol, and antigen retrieval was carried out using sodium citrate buffer for 30 min. Sections were then blocked by using goat serum and incubated overnight with anti-TDP-43 (abnova: E2 clone 1:1000). Next, labeling was detected by using species-specific biotinylated the EnVision™ + System, Peroxidase (Dako, Agilent). Slides were cover slipped using DPX mounting medium (#06522, Sigma). For the used tissues, we obtained written consent from the families for tissue removal after death for diagnostic and research purposes at the Neurological Tissue bank of the Biobank-Hospital Clínic-Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS). We also obtained tissue from control subjects stored at this Biobank. The study had the approval of the Ethics Committee of Hospital Clínic de Barcelona (CEIm). Features of the cases are shown in Additional file 1: Table S1.