Phages were injected i.v. into four groups of ICR mice. Rescued phages from the fourth round had a great augment (mean±S.D., n=3, *** p<0.005). (B) The time curve of brain/blood ratio of M13 phages titer. The accumulation of intact infectious phage particles in brains was analyzed by the ratio of phage particles in brain and in blood. The accumulation of phages in brain peaked at 24h. (mean±S.D., n=3). (C) Pep TGN competition with Clone 12-2. At the amount of 20μg, Pep TGN efficiently prevent the Clone 12-2 entering into the brain. (mean±S.D.), n=3 **p< 0.01, ***p<0.005).