TransDB3.1 Chemically Competent Cell is specifically designed for chemical transformation of DNA. This cell contains the gyrA462 gene which provides resistance to the toxic effects from the ccdB gene. TransDB3.1 Chemically Competent Cell can be used for transformation and propagation of plasmid containing the ccdB gene. It permits a transformation efficiency of over 108 cfu/μg DNA (tested by pUC19 plasmid DNA).