"Tubulofilamentous particles" are not scrapie-specific and are unrelated to tubulovesicular structures.

"Tubulofilamentous particles" has been defined as "thick" tubules, apparently distinguishable from other cytoskeletal elements, in touch-preparations from scrapie- and Creutzfeldt-Jakob disease (CJD)-infected brains. I report here that "tubulofilamentous particles" are nonspecific findings unrelated to "tubulovesicular structures" (TVS) which are the only particles consistently observed in brains of naturally occurring and experimentally induced SSVE.