What type of vector can be used to transfer insulin into E. coli?

To transfer insulin into E. coli, a plasmid vector is typically used. These plasmids can carry the insulin gene and contain elements such as an origin of replication, a promoter for transcription, and antibiotic resistance genes for selection. Commonly used plasmids for this purpose include pUC and pBR322. Once introduced into E. coli through transformation, the bacteria can express the insulin protein.