DNA is as old as life itself – but we have only really discovered what it looks like and how it works over the last 70 years or so.
Lots of scientists, working over many centuries, have been part of the process of helping to understand DNA.
When was DNA discovered?
About 150 years ago, humans got the first idea that DNA was in our cells, when biologist Friedrich Miescher identified it as a molecule in 1869.
Miescher, from Switzerland, made this discovery by chance in his work on white blood cells.
He isolated "nuclein," DNA with associated proteins, from cell nuclei, by collecting bandages from a nearby clinic and washing off the pus, which contains a lot of white blood cells.
DNA – or Deoxyribonucleic acid – got its name more than 15 years later, in 1885, thanks to German biochemist Albrecht Kossel.
But the spiralled, double-helix structure of DNA that we know today was not noticed for another 70 years after that, when it was discovered by English chemist Rosalind Franklin.
And two years later, in 1953, molecular biologists James Watson and Francis Crick published a paper describing the structure of DNA.
A lot of scientists had contributed ideas that made Watson and Crick’s breakthrough publication possible, and we are still finding out about DNA today.
DNA is a molecule containing the genetic information to reproduce and grow whole beings.
But genetics is not the whole picture of a being, which is further shaped by its experiences and environment.
An almost identical set of DNA can be found in the nucleus of every cell of the body, and we have another set of DNA in the mitochondria, which is the energy-producing part of the cell.
DNA has a structure like a twisted-up ladder, with sugars and phosphates forming the sides, while connected nitrogen bases pair up to form the rungs.
Who discovered DNA?
Fredrich Miescher was the first to identify DNA as a molecule in his work on white blood cells in 1869.
James Watson and Francis Crick published the first description of the structure of DNA almost 100 years later, in 1953.
Albrecht Kossel named DNA, and identified and isolated the five nucleotide bases needed in a stable DNA molecule – Guanine, Thymine, Cytosine, Adenine, and Uracil.
German biologist Walther Flemming was the first to set out the full process of cell replication, called mitosis, in 1882.
In 1984, British geneticist Professor Alec Jeffreys discovered DNA fingerprinting, which uses variations in the genetic code to identify individuals.
Jeffreys' DNA profiling – the process of determining an individual's DNA characteristic – is now used worldwide in forensic science to assist policeand in paternity disputes.
There are a wide range of plans for future research on DNA.
One is the expectation to enable the use of more personalised medical treatment.
Another is to improve our ability to tackle infectious and noninfectious diseases.
And we even hope to learn more accurately about our past through DNA found in fossils.
Timeline history of DNA:
- 1866: Father-of-genetics Gregor Mendel was the first to suggest that characteristics are inherited from one generation to the next, and some are more dominant than others.
- 1869: Fredrich Miescher isolated a molecule now known to be DNA from the nucleus of a cell.
- 1882: Walther Flemming discovered the process of mitosis, specifically the way chromosomes divide and double their number.
- 1885-1901: Albrecht Kossel named DNA and isolated the five nucleotide bases needed to make up a stable DNA molecule.
- 1902: Mendel's theories were associated with a human disease for the first time, and we began to understand the link between genetic errors and human disease.
- 1944: Medical researcher Oswald Avery outlined DNA as the 'Transforming Principle', that transforms cell properties. It was previously thought to be protein that did this.
- 1944-50: American biochemist Erwin Chargaff found that DNA was the molecule specifically responsible for genetic heritage, and to differ between species.
- Late 1940s: Physiologist Barbara Mclintock put forward the idea that genes are mobile and can move on chromosomes. The theory won her a Nobel prize.
- 1951: Rosalind Franklin discovered the helical form of DNA that we recognise today, while she was taking X-ray refraction photographs of it.
- 1953: The double-helical, spiral-ladder-like structure of DNA was set out in a paper by James Watson and Francis Crick. They discovered how information was stored in DNA and transferred to the next generation.
- 1984: Professor Alec Jeffreys discovered the variations in DNA, unique to each individual, known as genetic fingerprinting.
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