DB3.1屬于大腸桿菌克隆型菌種，DB3.1大腸桿菌菌株基因組中含有 gyrA462 基因，賦予其對λ嗜菌體的ccdB毒性基因的抗性，特別適用于構建或擴繁含有ccdB基因的質粒載體（例如GATEWAY System Vector) ，此菌株具有鏈霉素抗性。DB3.1需要在37℃有氧的條件下培養，可以使用20%的甘油在-80℃進行保種。用此大腸桿菌轉化質粒，可采用42℃熱激，進行轉化。 DB3.1制備感受態的時候請先用鏈霉素篩選菌種，在含有鏈霉素素抗生素的培養皿上四區劃線該菌株，挑取單菌落培養，然后再進行感受態制備操作。 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.
