Fig. 5.

Immunohistochemistry using an array of Aβ antibodies: qualitative analyses. Low magnification photomicrographs of Aβ (6E10) immunoreactivity in the frontal cortex of the [C-11]PiB(−) case (a) and the [C-11]PiB(+) case (b). Aβ immunoreactive plaques are observed in focal diffuse clusters in the [C-11]PiB(−) case, and are widely and densely distributed in the [C-11]PiB(+) case. Similar patterns of labeling were observed using antibodies generated against different amino acid (aa) sequences/forms of the Aβ peptide; plaques revealed using antibodies recognizing aa1-16 (6E10, c, h), N3pE (d, i), aa17–24 (4G8, e,j), x-40 (f, k), and x-42 (g, l) are only focally frequent in the [C-11]PiB(−) case (c–g), while they are abundant in the [C-11]PiB(+) case (h–l). Areas of highest plaque density are shown for both cases. Scale bar 500 μm (a, b); 200 μm (c–l)