In standard cloning protocols, the cloning of any DNA fragment essentially involves seven steps: (1) Choice of host organism and cloning vector, (2) Preparation of vector DNA, (3) Preparation of DNA to be cloned, (4) Creation of recombinant DNA, (5) Introduction of recombinant DNA into the host organism, (6) Selection of organisms containing recombinant DNA, and (7) Screening for clones with desired DNA inserts and biological properties.
Following transplantation into the host organism, the foreign DNA contained within the recombinant DNA construct may or may not be expressed.
The choice of vector for molecular cloning depends on the choice of host organism, the size of the DNA to be cloned, and whether and how the foreign DNA is to be expressed.
The DNA segments can be combined by using a variety of methods, such as restriction enzyme/ligase cloning or Gibson assembly.
Construction of recombinant DNA, in which a foreign DNA fragment is inserted into a plasmid vector.
In this example, the gene indicated by the white color is inactivated upon insertion of the foreign DNA fragment.
One is that molecular cloning involves replication of the DNA within a living cell, while PCR replicates DNA in the test tube, free of living cells.
The other difference is that cloning involves cutting and pasting DNA sequences, while PCR amplifies by copying an existing sequence.
Because of this, DNA cloning is also called recombinant DNA technology.
DNA cloning is used to create a large number of copies of a gene or other piece of DNA.