Joining of vector molecules and DNA of interest is the final step in the construction of a recombinant DNA molecule. The process is called ligation and the enzyme that catalyzes this reaction is called DNA ligase. As it helps in joining of the desired DNA segment to the cloning vector, it is also called molecular glue.

pBR322 is a synthetic plasmid created in 1977 in the laboratory of Herbert Boyer at the University of California.

Insulin is produced by recombinant E. coli cells which are genetically modified to produce Insulin.

EcoRI is a restriction endonuclease enzyme isolated from the bacterial species of E. coli.