Table 1.
Helper phage name | Mutation/mechanism | aHelper phage titers/ml | Display levels | a,bRescued phagemid titers/ml | Use in display | Helper phage propagation | Reference |
---|---|---|---|---|---|---|---|
M13K07 | 1011c | Low | 2 × 1010−12 | Standard infection | Growth | (67) | |
KM13 | Trypsin site in g3p, elution with trypsin | 1011 | Low | 2 × 1010−12 | Standard infection | Growth | (38) |
g3 deletion | 105−6 | High | ∼1010 | Standard infection | g3 plasmid expression under lac promoter | (68) | |
M13MDD3.2 | g3 deletion | 2 × 109 | NT | 109 | Standard infection | g3p plasmid expression | (33) |
R408d3 | g3 deletiond | 1010 | NT | NT | Standard infection | g3p plasmid expression under pspA promoter | (27) |
Hyperphage | g3 deletion (8-406) | 109 | High | 109−10 | Standard infection | g3p integrated into E.coli genome | (35) |
CT helper phage | g3 N1 & N2 domains deletede | 3 × 1011 | Low | 1011 total 5 × 108 infective | Standard infection | g3p plasmid expression | (37) |
Ex-phage | Amber stop codon 5′ g3 | 1012−13f | High | 1010−11 | Non-suppressor strain | Suppressor strain | (36) |
Phaberge | Amber stop codon 3′ g3 | 1011 | High | 109−10 | Non-suppressor strain | Suppressor strain | (34) |
The mechanisms of action, as well as the reported titers of both packaged phage and helper phage are given. NT-not tested.
aTiters are unconcentrated supernatant titers—i.e. not PEG precipitated.
bRefers to the number of infectious phagemid particles, independent of whether they carry antibody or no.
cData from our laboratory.
dSome reversion due to packaging of plasmid expressing p3 observed-probably also occurs in other plasmid expression systems, but not examined.
eRescued phagemid are two populations, displaying and infective, non-displaying and non-infective.
fStandard M13K07 titers obtained in this laboratory tend to be 10–100-fold higher than obtained elsewhere.