Figure 4.

Aβ monomer is specifically detected in Tris-buffered saline (TBS) and Tris-buffered saline containing 1% TX-100 (TBS-TX) extracts of Alzheimer brain. Average quantifiable monomeric (∼4 kDa) Aβ detected in duplicate homogenates of temporal (A–C) and frontal (D–F) cortices from 43 human brains. The presence of dementia was based on the most recent participant interview, information from death certification, and a retrospective informant interview. Alzheimer’s disease was defined as a donor with dementia plus a pathological CERAD rating of probable/definite Alzheimer’s disease. All samples with detectable levels of Aβ are indicated by black open triangles and those lacking detectable Aβ are shown as red filled circles. ND = not demented, n = 19; DNAD = demented not Alzheimer type, n = 10; AD = Alzheimer Disease, n = 14; FA = formic acid.