Additional file 3: Figure S3. Signal Intensities of 23 Different Phages with Preferential Reactivity for ALS Related TDP-43 Variants. Indirect phage ELISAs using 23 different previously isolated clones with preferential reactivity for ALS TDP-43 variants were completed with homogenized brain tissue from ALS, FTD and healthy samples (motor cortex). All the phages generated increased reactivity with ALS brain tissue compared to both FTD and control cases. The ratio of ALS to control tissue for each phage was first calculated, followed by subtraction of the binding ratio produced with FTD brain tissue. The results of ALS relative to FTD are shown. Bound phages are detected with an anti-M13-HRP antibody.