Rosetta-gami™ 2 host strains combine the advantages of Rosetta 2 and Origami 2 strains to alleviate codon bias and enhance disulfide bond formation in the cytoplasm when heterologoous proteins are expressed in E. coli.

• Guaranteed efficiency: 2×10⁶ cfu/µg

These trxB/gor mutants are compatible with kanamycin-resistant vectors, and carry the chloramphenicol-resistant pRARE2 plasmid, which supplies seven rare tRNAs.

DE3 indicates that the host is a lysogen of λDE3, and therefore carries a chromosomal copy of the T7 RNA polymerase gene under control of the lacUV5 promoter. Such strains are suitable for production of protein from target genes cloned in pET vectors by induction with IPTG.

pLysS strains express T7 lysozyme, which further suppresses basal expression of T7 RNA polymerase prior to induction, thus stabilizing pET recombinants encoding target proteins that affect cell growth and viability.