The invention concerns a method for inducing somatic mutations in vitro or ex vivo, comprising (1): adding to the cells to be mutated, in culture conditions and in a medium suited to said cells, of at least a combination of anti-IgM and anti-CD19 and/or anti-DC21 antibodies, while (2) said anti-IgM antibodies are biotinylated and are subjected to specific aggregation by streptavidin coupled with a support. Advantageously, the mutations are controlled and/or adjusted by inhibiting and reactivating and/or stimulating DNA polymerase pol iota. The invention is in particular applicable to rapid and controlled induction of mutations on the BL2 Burkitt's lymphoma.