Representative sections of gut, spleen, and brain stained for abnormal PrP at sequential times after ic inoculation. (A – C) No pathologic PrP is observed four days after inoculation. (D – F) Only lymphoid tissues are positive 32 days after inoculation. (G – I) Clinically ill mice show abnormal PrP accumulation in brain as well as in lymphoid tissues 120 days after inoculation. The arrow in H shows a positive cell outside the germinal center that is morphologically consistent with a macrophage or dendritic cell. Methods for inoculation, fixation and detection of PrP detection have been described previously .