What is molecular cloning?

Molecular cloning is a set of laboratory methods used to assemble recombinant DNA and direct their replication within host organisms. DNA sequences from two different organisms are generally used by molecular cloning: the species carrying the DNA to be cloned, and the species serving as the living host for replication of the recombinant DNA. The DNA to be cloned is first obtained from the organism of interest, followed by treatment with enzymes to generate smaller DNA fragments in the test tube. Then, these DNA fragments are combined with vector DNA to generate the recombinant DNA molecules. After being introduced into a host organism, these recombinant DNA molecules are replicated along with the host DNA, resulting in exponential replication.