Competent Cells

The low cost and convenience of expressing mammalian proteins in E. coli make this host bacterium an important tool for life science applications ranging from protein function studies to X-ray crystallography. However, a major obstacle faced by scientists using E. coli expression strains, such as BL21(DE3), is the high percentage of mammalian proteins that are expressed in an insoluble form. Using a directed evolution approach, Genlantis scientists have developed a mutant strain of BL21(DE3) E. coli that can produce soluble protein in the majority of cases where expression in the parent BL21(DE3) yields no detectable soluble product.