Bacterial Strain LE392 is used for both genomic and cDNA cloning. LE392 lacks the E. coli K restriction system but is rec+. It is a
permissive host, allowing both recombinant and parental phage to grow. Unlike Y1090, LE392 does not allow color selection of recombinants or IPTG induction of expression. Also, since LE392 contains lon protease activity, fusion proteins are often less stable in this host than in Y1090. When using this strain, phage titers tend to be higher than with Y1090 host cells. Therefore, we recommend (if color selection is not required) that LE392 be the primary strain for amplification of recombinant phage and for screening a cDNA library with nucleic acid probes.
Genotype: hsdR514(rk–, mk+), glnV(supE44), tryT (supF58), lacY1 or Δ(lacIZY)6, galK2, galT22, metB1, trpR55.