DB3.1属于大肠杆菌克隆型菌种，DB3.1大肠杆菌菌株基因组中含有 gyrA462 基因，赋予其对λ嗜菌体的ccdB毒性基因的抗性，特别适用于构建或扩繁含有ccdB基因的质粒载体（例如GATEWAY System Vector) ，此菌株具有链霉素抗性。DB3.1需要在37℃有氧的条件下培养，可以使用20%的甘油在-80℃进行保种。用此大肠杆菌转化质粒，可采用42℃热激，进行转化。 DB3.1制备感受态的时候请先用链霉素筛选菌种，在含有链霉素素抗生素的培养皿上四区划线该菌株，挑取单菌落培养，然后再进行感受态制备操作。 DB3.1 Competent Cells have been prepared by apatented modification of the procedure of Hanahan (1). These cells contain the gyrA462 allele which renders the strain resistant to the toxic effects of the ccdB gene (2). DB3.1 Competent Cells can be used for propagating plasmids containing the ccdB gene such as GATEWAY System vectors or for constructing new plasmids containing the ccdB gene.
