Homologous recombination is a very important cellular process, as it pro-vides a major pathway for the repair of DNA double-strand breaks. This complex process is affected by many factors within cells. Here, we have studied the effect of monovalent cations (K + ,Na + , and NH4 + ) on the outcome of recombination events, as their presence affects the biochemical activities of the proteins involved in recombination as well as the structure of DNA.