Any reference about the genetic of E.coli DH5alpha, what their specialty, what gene do they have and don't, ect. Why are they always used in transformation and blue white selection? I also can't find the gene map of plasmid pET-14b inserted by lacZ gene in correct and wrong orientation.
DH5α
F- endA1 glnV44 thi-1 recA1 relA1 gyrA96 deoR nupG Φ80dlacZΔM15 Δ(lacZYA-argF)U169, hsdR17(rK- mK+), λ–
An Hoffman-Berling 1100 strain derivative (Meselson68)
Promega also lists phoA
nalidixic acid resistant
References:
FOCUS (1986) 8:2, 9.
Hanahan, D. (1985) in DNA Cloning: A Practical Approach (Glover, D.M., ed.), Vol. 1, p. 109, IRL Press, McLean, Virginia.
Grant, S.G.N. et al. (1990) Proc. Natl. Acad. Sci. USA 87: 4645-4649 PMID 2162051.
Meselson M. and Yuan R. (1968) Nature 217:1110 PMID 4868368.
http://openwetware.org/wiki/E._coli_genotypes#DH5.CE.B1
http://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCoQFjAA&url=http%3A%2F%2Fwww.helmholtz-muenchen.de%2Ffileadmin%2FPEPF%2FpET_vectors%2FpET-14b_map.pdf&ei=UzIjU_6WK4KMrgeVtYCQAQ&usg=AFQjCNEkzpsIO6N_7332dmZBlcm1hT6SAA&sig2=koUE0dgtSgdwCdNnAP-NWw
For DH5alfa, see page 110 at http://tools.lifetechnologies.com/content/Focus/Focus%20Volume%2015%20Issue%204.pdf
For pET14b, see http://www.helmholtz-muenchen.de/fileadmin/PEPF/pET_vectors/pET-14b_map.pdf
There have been far better cloning strains than DH5 alfa out there for years. People continue to use it out of habit mainly (why fix what ain't broken?). It is an endA/recA host (higher plasmid prep yield/quality and better plasmid stability, no catenanes, etc) that offers alpha complementation (blue/white screening) and can be made competent at reasonably high frequency.