Transformation is one of three processes by which outside genetic material may be got into bacterial cells . The other two are conjugation ( transfer of genetic material between two bacterial cells in direct contact ) , and transduction ( injection of foreign DNA by a bacteriophage into the host ) . Transformation is one of three processes by which exogenous genetic material may be introduced into bacterial cell , the other two being conjugation ( transfer of genetic material between two bacterial cells in direct contact ) , and transduction ( injection of foreign DNA by a bacteriophage into the host ) .