What is recombinant DNA?

What recombinant DNA is

Recombinant DNA is a single DNA molecule assembled from sequences that did not originally occur together — for example, a human gene joined to a bacterial plasmid. It is made by cutting DNA from different sources with restriction enzymes and joining the pieces with an enzyme called DNA ligase. When the recombinant molecule is introduced into a host cell, the cell copies it and may express the inserted gene, producing the corresponding protein.

The 1973 breakthrough

The first recombinant DNA molecules were created in 1973 by Stanley Cohen and Herbert Boyer, who inserted foreign DNA into a plasmid and showed that bacteria taking up the plasmid would copy the inserted DNA.

This demonstration that genes could be deliberately moved between organisms opened the era of genetic engineering and prompted early discussions — notably the 1975 Asilomar conference — about how to conduct such research responsibly.

Significance in research

Recombinant DNA technology underlies much of modern molecular biology and biotechnology. It allows researchers to clone genes, produce proteins in cultured cells, and study gene function. Because recombinant constructs are shared and reproduced across laboratories, precise, standardised description of their components and sequences is important for reproducible and reusable research. This page describes the science and history of recombinant DNA and is not medical advice.