Heteroduplex mobility assay (HMA) pre-screening: An improved strategy for the rapid identification of inserts selected from phage-displayed peptide libraries

Phage-displayed peptide libraries represent an efficient toolto isolate peptides that bind a given target molecule. Afterseveral selection rounds, generally a large pool of targetbinding phages is obtained. Conventional analysis of theselected phage population involves extensive sequencing of many clones, mostof which can be identical. We have adapted the HeteroduplexMobility Assay (HMA) for pre-screening of phage inserts thatwere amplified by direct colony PCR of ELISA-positive clones.This strategy allowed for the rapid and reproducible assignment ofinsert sequences to different `heteroduplex migration groups'.Sequence analysis of only one representative of each HMAmigration group then completes the characterisation of thebinding phage population. In our model experiments,only 16% of HMA pre-screenedclones required further sequence analysis.