Expression of βAPP, CTF, and Aβ in brain and systemic organs of Tg2576 and nontransgenic mice. Immunoblots in A–F were labeled with anti-C (Saeko) (A, C, E), which detects both human and mouse βAPP, or with 6E10 (B,D, F), which specifically detects human βAPP. A, B, Immunoblots of βAPP and CTF in transgenic and nontransgenic mice of various ages (months). Immunoblots were prepared from 16% Tricine gels. C–F, Immunoblots of SDS extracts from systemic organs of a 10.9 month Tg2576 mouse (C, D) and a 9.3 month nontransgenic mouse (E, F). Immunoblots were prepared from 10–20% Tricine gels loaded at 20 mg/lane total protein. Tg, Transgenic;NTg, nontransgenic; Br, brain;H, heart; Lg, lung; Lv, liver; K, kidney; P, pancreas;Sp, spleen; St, stomach;Si, small intestine; Li, large intestine;M, muscle; Bo, bone; Sk, skin. G, Immunoblot of Aβ in SDS and FA extracts of systemic organs. The Aβ in SDS extracts (40 μl) was analyzed by 4G8 immunoprecipitation followed by immunoblotting with 4G8; FA acid extracts (40 μl), dried and resuspended, were also analyzed by immunoblotting with 4G8. H, Total Aβ (Aβ42 plus Aβ40) in SDS and FA extracts of systemic organs. Aβ42 and Aβ40 were analyzed by 3160/BC-05 and 3160/BA-27 ELISAs, respectively.