Isolation of monoclonal antibodies recognizing rare and dominant epitopes in plant vascular cell walls by phage display subtraction.

A combination of phage display antibody technology and a subtraction method provides a powerful tool for the isolation of novel biomarkers. However, the dilemma that high stringency screening often reduces the diversity in the subtracted phage antibody repertoires and that it is difficult to isolate phage antibody against rare epitopes remain. Therefore, we carefully monitored the occupancy of differentiation-specific clones in a phage antibody library through an enrichment process, and succeeded in isolating monoclonal antibodies against rare and dominant epitopes in plant vascular cell walls. We also report that clones with stop and frameshift mutations significantly survived the enrichment process, owing to noncanonical translation mechanisms.