The ability to vary the resistance on the electroporation machine is recommended for electroporation of P. syringae pv. syringae strains. Several of the strains exhibit greater electroporation efficiencies at higher resistances. For many P. syringae pv. syringae strains, standard E. coli conditions can be used for electroporation (although they will be less efficient) and, therefore, any brand of electroporator will work.