Fig. 2
Previous contact with external pathogens is not necessary for the presence of anti-neo-epitope IgMs in mouse serum. Representative images of the hippocampal region of brain sections from 12-month old ICR-CD1 mice simultaneously stained with Hoechst (blue), anti-MMP-2 antibody (green) and sera (red) from a 3-month-old ICR-CD1 SOPF animal (a) or from a 3-month-old BALB/C SOPF animal (b). In both cases the anti-MMP-2 staining showed the clusters of granules. Some granules of the clusters are stained with the serum, indicating that the sera of SOPF animals contained anti-neo-epitope IgMs. Scale bar: 50 μm