Old and young donors cells show different ability to homologous recombination (shown on the first stage--the chromosome transference) in vitro, that we suppose could be the reasons of the genome instability in aging. Homologous recombination, induced by X-radiation, is limited in cells taken from donors older than 70 years. Alpha-amanitin, the RNA-polymerize II repressor, in toxic doze, could induce the chromosome transference in the cells from all studied groups: from old and young donors and donors with repair process defect (with BRCA 1, 2 mutations). Summarized effect of X-radiation and alpha-amanitin does not increase the induction of the chromosome transference.