The Ph.D. Peptide ligands for a variety of targets can then be selected by the straightforward method of panning.

The supplied display vector M13KE is an M13 derivative with cloning sites engineered  for  N-terminal pIII fusion, resulting in a valency of 5 displayed peptides per virion. The use of a phage vector, rather than a phagemid, simplifies the intermediate amplification steps, since neither antibiotic selection nor helper phage superinfection are required. Since displayed proteins longer than 20–30 amino acids have a deleterious effect on the infectivity function of pIII in phage vectors, this vector is suitable only for the display of short peptides. Included with the cloning vector is an insert extension primer as well as a detailed protocol for cloning a peptide library into M13KE. M13KE infectious phage particles are also available.

Peptide Display Cloning System facilitates the display of custom peptide libraries on the surface of bacteriophage M13 as coat protein fusions, creating a physical linkage between each displayed peptide and its encoding DNA sequence.