(August 2004) Genetic Carrying Handles: Cloning Vectors In order to clone a gene, its DNA sequence must be attached to some kind of carrier, also made of DNA, that can take it into the cell. Biologists call these carriers vectors. A vector acts like a handle for the DNA, and it also contains other tools such as an origin of replication and a selective marker. The origin of replication is a sequence of DNA that the host cell recognizes that allows it to make more copies of the clone DNA sequence. This origin sequence is where the cell begins copying…