Fig. 2. Representative β-amyloid (Aβ) immunoreactivity patterns by diaminobenzidine immunohistochemistry with hematoxylin counterstaining.

The Aβ immunoreactivity patterns are shown in four adjacent sections of the same neocortex blocks obtained from an HIV-infected person (a−d) and a symptomatic Alzheimer’s disease patient (e−h). Plaque deposits of generic 4G8 (a and e, widespread density), N3pE (b and f, widespread), E22P (c and g, focal), and phospho-Ser8 (d and h, focal) Aβ forms are depicted; scale bar, 300 μm for (a−h). High-magnification images of Aβ plaques (arrows) are shown in the corresponding insets. Diffuse and cored Aβ plaques are illustrated in (a) and (b) insets, respectively.