TARDBP and amyotrophic lateral sclerosis: Equivalent amounts of low salt, high salt Triton X-100 and urea fractions were immunoblotted with polyclonal TDP-43 antibody (Proteintech), which immunolabeled full-length TDP-43 in all fractions but also a distinct 35-kDa species that was only present in the urea fraction of ALS samples (Online Resource 2).