A help in generating more primary clones

X packaging A help in generating more primary clones 

The redox potential of the bacterial cell is of a reducing nature compared to that in the eukaryotic cytoplasm. This has a negative effect on the folding of eukaryotic proteins 

In conclusion, these feasibility exercises were successful, but I am presently unaware of their use in actual library construction or selective panning. The alternative system for cytoplasmic expression, which has been well characterized in generating gene banks and panning selection, is the plasmid-protein-complexlisplay system (also called peptides-on-plasmids ) developed by Schatz [127-130] using extensions to the C-terminus of the lac-repressor. This is not a phagemid system, since the plasmid DNA is naked and is reintroduced into the cell by transformation. 

Two other bacteriophage systems have also been investigated as potential phage-display vectors, namely bacteriophage T4 [131], where a C-terminal extension on fibritin encoded by gene wac (whisker s antigen control) could be displayed, and P4 [132], where a deca-peptide was successfully inserted and presented near the N-terminus of the capsid decoration component, Psu. Their relative usefulness cannot yet be evaluated. 

A number of references throughout this review mention the importance of constraints within the displayed epitope in finding strong binding clones (e.g. Refs. 5, 9, 72, 133 and 

---