In the Allen lab phage display (PD) is a technique used to screen a large number of peptides on materials of interest for further research. The standard protocol is too take a library containing a large concentration of phage that each express different binding peptides on one end. The phage are allowed to mix with the materials in solution so binding can occur. Weak binders are removed in a series of washes. The strongest binding phage are taken and amplified in e-coli. This new sample of phage is then use in another round of PD. After several rounds of PD the phage are allowed to infect cells on growth media plates. The plaques formed from infection at then sequenced and the peptides expressed on each phage are stored in a lab catalog. When a peptide has been seen several times for a specific material and no others it is considered a strong candidate and taken to the next part of a project. Below is an image of the standard steps involved in PD.