Takara's pCold Expression Vectors offer cold shock expression technology for high purity, high yield protein production. The series includes four different vectors that utilize the cold shock Protein A (cspA) promoter to direct expression of recombinant protein in E. coli. These vectors selectively induce target protein synthesis at low temperatures (15°C) when the synthesis of other proteins is suppressed and protease activity is decreased. This results in high yield of the target protein (60% of intracellular protein). In addition to the cspA promoter, all four vectors contain a lac operator (for control of expression), ampicillin resistance gene (amp^r), ColE1 origin of replication, M13 IG fragment, and multiple cloning site (MCS). Furthermore,pCold III DNA contains a translation enhancing element (TEE). These vectors work equally well for synthesis of non-labeled and radiolabeled proteins and can be used in conjunction with Takara's Chaperone Plasmid Set (Cat. # 3340).

NOTE: For commercial use of this product, please refer to the protein expression vectors for commercial use page for ordering information. 

Stellar Competent Cells are an E. coli HST08 strain that provides high transformation efficiency. These cells can be used in a wide variety of applications—from preparation of cDNA and genomic libraries, to construction of longer-length genomic libraries, to subcloning, and even methylated DNA cloning. Stellar Competent Cells lack the gene cluster for cutting foreign methylated DNA (mrr-hsdRMS-mcrBC and mcrA), and are therefore useful for cloning methylated DNA. The cells can also be used for blue/white screening (i.e., α-complementation) when transformed with vectors containing the lacZα gene. A pUC19 vector is provided as well as SOC Medium. Stellar Competent Cells are recommended for use with Clontech's In-Fusion PCR Cloning Kits.