3/ Smith also helped to discover rare and unexpected modifications of DNA bases in bacterial genomes which are now understood to prevent attack from DNA viruses.

2/ Smith helped to elucidate the structure of ribonucleic acid molecules (RNA), the genetic material of many plant and animal viruses. This was helped by his development of paper chromatographic methods for analysing nucleosides and other units which make up DNA

3/Cech discovered that unprocessed RNA molecules could splice themselves and showed that RNA molecules are not restricted to being passive carriers of genetic information.

2/ Cech made the discovery while investigating the splicing RNA in Tetrahymena thermophila, a unicellular organism, during the 1970s.

2/ In 1929 Moore played a pivotal role in isolating the testicular secretion containing the male sex hormones andresterone and testosterone. This discovery opened up the path to researching the chemical composition of the hormones and their production.

3/ The Cori's work earned them the 1947 the #NobelPrize for Medicine together with Bernando Hossay.

2/ In 1943 Carl and Gerty managed to isolate and purify glycogen phosphorylase. They hypothesised that liver glycogen first converts to blood glucose and then reconverts to glycogen in the muscle, where it is broken down into lactic acid which provides the energy used in muscle contraction.

4/ Born to Jewish parents, Koprowski was forced to flee Poland in 1939 after Germany invaded the country. For more about his life and work see 'https://www.whatisbiotechnology.org/index.php/people/summary/Koprowski'

3/ Koprowski went on to become the director of the Wistar Institute where in the 1960s he led efforts to improve the rabies vaccine. He subsequently became the first scientist, together with colleagues, to hold a patent for monoclonal antibodies.

2/ In January 1948 Koprowski injected the vaccine into himself. The vaccine had the advantage that it directly entered the intestinal tract and provided long-lasting immunity. Within a decade the vaccine had been adopted on four continents

3/ For more about phages and how they have become an important therapeutic tool see www.whatisbiotechnology.org/index.php/sc...

2/ Twort's finding was initially ignored until after Félix d'Herelle independently also noted phages in 1917. Phages are now an important tool in molecular biology.

2/ Hershey shared the 1969 #NobelPrize for Medicine for 'discoveries concerning the replication mechanism and the genetic structure of viruses.' For about Chase and Hershey's famous experiment see www.whatisbiotechnology.org/index.php/ex...

3/ Despite his discovery, Finlay's work went largely unheeded until 1900 when the US Army Yellow Fever Board confirmed his findings. This paved the way to measures to control the mosquito population to prevent the spread of yellow fever.

2/ Finlay first proposed this idea in 1881 to the International Sanitary Conference. A year later he identified the specific mosquito species, Culex fasciatus (now known as Aedes aegypti), that carries the disease.

Kuhn finally accepted the Nobel Prize after World War II. Kuhn is also credited with the discovery of Soman, a deadly nerve agent, in 1944.

3/ Initially Kuhn turned down the Nobel Prize because he was forbidden to accept it by the Nazis with whom he collaborated in the denouncement of three of his Jewish colleagues.