Compared to the hybridoma technique, phage display technology offers significant advantages. The hybridoma method is limited to mice, rats, hamsters, and guinea pigs. In contrast, phage display can be used to generate high-affinity monoclonal antibodies from all common antibody-producing species, including but not limited to humans, mice, rats, rabbits, chickens, camels, camels, alpacas, cattle, dogs, sheep, monkeys, and sharks. Hybridoma-based monoclonal antibody development can generate only a small number of candidate antibodies against a specific immunogen at a time; in contrast, phage display technology can present the entire antibody repertoire of the immunized animal, of which nearly 10% are immunogen-specific. Given such a vast potential library of binding agents, the chances of discovering antibodies with the desired characteristics using phage display technology are much greater, and phage screening offers short turnaround times and flexible experimental design.

Depending on the specific target molecules, they can be broadly classified into the following two categories: 1) Proteins/Antibodies: Diagnostics, drug targeting, protein structure analysis, humanization, and custom antibodies for scientific research. 2) Random peptide libraries: Protein-protein interactions (ligand-receptor, signal transduction, antagonists/inhibitors, etc.), protein-DNA interactions, diagnostics, neutralizing activity, etc.

In phage display technology, auxiliary phages containing the pⅢ phage display vector are typically used to infect E. coli to produce phage particles. The expression of fusion proteins in these particles follows a Poisson distribution: approximately 90% of the particles display only the wild-type pⅢ protein, less than 10% display a single copy of the fusion protein, and cases where multiple copies are displayed are extremely rare. Consequently, most fusion proteins are displayed in a monovalent form. Compared to multivalent display, monovalent display allows for the removal of weakly binding antibodies during the screening process. In contrast, multivalent display, due to the avidity effect, tends to enrich even weakly binding clones.

Improper storage methods can reduce the titer of phages. In principle, phage libraries stored in 50% glycerol at low temperatures (below -80°C) can be preserved for a relatively long time.