Table 1.

Various display technologies

Technology (typical number of sequences screened per library)	Description	Strengths or weaknesses
Bacterial cell display (108–109)	Fusion gene libraries of the target proteins and bacterial surface proteins Fusion proteins are displayed on bacterial cell surface	Selects proteins displayed on bacterial cell surfaces Flow cytometry allows multiparameter, quantitative screening Smaller library size Cannot screen proteins that would be toxic to cells
Yeast or mammalian cell display (108–1010)	Fusion gene libraries of the target protein and cell surface proteins of yeast or mammalian cells Fusion proteins are displayed on cell surface	Selects proteins displayed on eukaryotic cell surfaces Flow cytometry allows multiparameter, quantitative screening Smaller library sizes Cannot screen proteins that would be toxic to cells
Phage or baculovirus display (1011)	Fusion gene libraries of the target protein and phage or virus coat proteins Infected bacteria produces phage or virus particles displaying fusion protein libraries on the surface	Robust and quick Cannot screen proteins that would be toxic to cells
Ribosome display (1015)	mRNA-target protein complexes are displayed on stalled ribosomes in cell free protein synthesis system Reverse-transcription PCR allows amplification after rounds of selections	Large library size Can screen proteins that would be toxic to cells Requires stringent conditions and stable proteins
mRNA display (1015)	mRNA-target protein fusions are synthesized in cell free protein synthesis system by conjugating them through a puromycin linker Reverse-transcription PCR allows amplification after rounds of selections	Large library size Can screen proteins that would be toxic to cells Works well with small proteins but not large ones Requires stringent conditions