FAQ: What strain should I use to titer or amplify M13KE?

A strain of E. coli with F' (F-pilus) notation in its genotype should be selected. We routinely titer and amplify M13KE in ER2738 (#E4104S), which has a tetracycline selectable F-pilus. NEBTurbo (#C2986) or NEB-5-alpha (#C2987, C2988) are also suitable. This product, #N0316S, and any of our three Ph.D.TM libraries (#E8100S, #E8110S or #E8120S), contain infectious M13 particles; competent cells are not needed. If using the Ph.D.TM Peptide Display Cloning System (#E8101S), competent cells are necessary.