E. coli host strain ER2738 is a robust F+ strain with a rapid growth rate and is particularly well-suited for M13 propagation. ER2738 is a recA+ strain, but we have never observed spontaneous in vivo recombination events with M13 or phagemid vectors Commercially available F+ strains such as DH5αF´and XL1-Blue can probably be substituted for ER2738, but have not been tested with our vector system Any strain used should be supE (GlnV)in order to suppress amber (UAG) stop codons within the library with glutamine.
Introduction
Strains Resistance Tet
Culture Medium LB
Condition 37℃ ,under the aerobic conditions
1. E. coli host strain ER2738 is a robust F+ strain with a rapid growth rate and is particularly well-suited for M13 propagation.ER2738 is a recA+ strain, but we have never observed spontaneous in vivo recombination events with M13 or phagemid vectors Commercially available F+ strains such as DH5αF´and XL1-Blue can probably be substituted for ER2738, but have not been tested with our vector system Any strain used should be supE (GlnV)in order to suppress amber (UAG) stop codons within the library with glutamine
2 Because M13 is a male-specific coliphage, it is recommended that all cultures for M13 propagation be inoculated from colonies grown on media selective for presence of the F-factor, rather than directly from the glycerol culture The F-factor of ER2738 contains a mini-transposon which confers tetracycline resistance, so cells harboring the F-factor can be selected by plating and propagating in tetracycline-containing medium Tetracycline does not need to be added to media during phage amplification
3 Streak out ER2738 from the supplied glycerol culture onto an LB+Tet plate. Invert and incubate at 37°C overnight and store wrapped with parafilm at 4°C in the dark for a maximum of 1 month. For archival purposes, we recommend that fresh glycerol stocks of ER2738 prepared from liquid cultures
4 ER2738 cultures for infection can be grown either in LB or LB+Tet media Loss of F-factor in nonselective media is insignificant as long as cultures are not serially diluted
Genotype
F´ proA+B+ lacIq Δ(lacZ)M15 zzf::Tn10 (TetR)/fhuA2 glnV Δ(lac-proAB) Δ(hsdMS-mcrB)5 [rk– mk–McrBC–]
