DNA discovered: Feb. 28, 1953

Like a lot of other scientists at the time, Cambridge professors James Watson and Francis Crick had spent several years trying to unlock the secret of deoxyribose nucleic acid, better known as DNA.  It’s a molecule thought to contain the human genetic code, but researchers had been unable to figure out how it did so and how that code was passed on from one generation to the next.

On this February morning, the pair finally figure out DNA’s double helix structure that allows it to “unzip” to create copies of itself.  Soon afterwards, at a nearby pub called The Eagle, Crick announces to other professors that he and Watson have “found the secret of life.”  When Watson gets home that night, he tells his wife that “we seem to have made a big discovery,” but she was not impressed because she had heard him say that before.

But it is a huge discovery. After seeing x-ray photography by another DNA researcher, Rosalind Franklin, Crick and Watson concluded that a DNA molecule was made of two chains of nucleotides, each in a helix, but one going up and the other going down. This suggested that each strand of the DNA molecule was a template for the other. During cell division, the two strands separate and on each strand a new “other half” is built, just like the one before. That way DNA can reproduce itself without changing its structure.

Two months later, they published a one-page report on their finding in the journal Nature, including a schematic drawing of the double helix by Crick’s wife, Odile. For their breakthrough, they, along with another researcher, Maurice Wilkins, were awarded a Nobel Prize in 1962. But Rosalind Franklin, whose work had been key to the double helix discovery, did not receive the award because she had died of ovarian cancer in 1958 and Nobel Prizes were given only to living scientists.

Among the advances that followed directly from the discovery of DNA’s structure were pre-natal screening for disease genes; genetically engineered foods; the ability to identify human remains; the rational design of treatments for diseases such as AIDS, and the accurate testing of physical evidence in order to convict or exonerate criminals.

Crick and Watson would have a falling-out over Watson’s book, The Double Helix, which was published in 1968. Crick didn’t like the way Watson had portrayed him and other researchers and considered the book a betrayal of their friendship. Watson, who was associated with the National Institutes of Health in the U.S. between 1988 and 1992, helped to establish the Human Genome Project, which mapped all human genes. He’s now 86 and lives in Chicago.

Crick died of colon cancer in 2004.  He was cremated and his ashes were spread in the Pacific Ocean.

More slices of history

Alka Selter is born: Feb. 21, 1931

First penicillin shot: Feb. 12, 1941

Longest surgery: Feb. 4-8, 1951

First Social Security check: Jan. 31, 1940

**Birth of canned beer: Jan. 24, 1935
**