molecular biology

César Milstein, a molecular biologist and winner of the 1984 Nobel Prize for Physiology or Medicine. This photograph was taken in the Medical Research Council Laboratory of Molecular Biology, Cambridge, where Milstein and his colleagues developed monoclonal antibodies, the achievement for which his Nobel Prize was awarded.

Study of the molecular basis of life, particularly using modern methods of working with DNA, to look at the structure and function of the components of living cells and to answer wider biological questions.

While there are no clear boundaries between molecular biology and biochemistry on one side and genetics on the other, molecular biology typically uses analysis and manipulation of genes to address biological questions concerning the corresponding proteins, or biological functions at cellular or higher level. In contrast, biochemistry aims more at studying the proteins (or other biomolecules) concerned, while genetics is mainly concerned with the gene specifically and the regulatory elements around it.

The discovery of the double helix structure of DNA by biologists Francis Crick and James Watson is often seen as the beginning of modern molecular biology. Later on, the field was defined by a set of key tools, including: restriction enzymes, which allow researchers to edit DNA and clone genes into the genomes of bacteria; the polymerase chain reaction (PCR), which makes it possible to produce large numbers of copies of a very small sample of DNA; site-directed mutagenesis; high-throughput screening methods such as microarrays; high-throughput gene sequencing as used in the genome projects; and RNAi, which is used to specifically and reversibly silence a gene of interest.

Application of such tools has been extremely successful since the 1980s, revolutionizing the way in which biochemical and biological questions are addressed, to an extent that now most life sciences research will involve some methods of molecular biology.

In a backlash aimed at reviving the more chemical side of biochemistry, chemical biology has recently emerged as a new discipline.