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This was the continuation of work by Frederick GriffithFrederick Griffith was a medical officer in London. In what is today known as Griffith's experiment, he discovered a transforming principle, which is today known as DNA. Griffith was, in fact, trying to make a vaccine to prevent pneumonia infections in th in 1928Centuries: 19th century 20th century 21st century Decades: 1870s 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s Years: 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 See also 1928 in aviation 1928 in film 1928 in literature 1928 in mu. Alfred HersheyThe nobel prize winning bacterologist Alfred Day Hershey was born in Owosso, Michigan, USA on December 4th 1908. Died 1997 1930: Received his B. in chemistry at Michigan State University 1934: Hershey recieved his Ph. in bacteriology at Michigan State Uni and Martha Chase continued this work in 1952 with the Hershey-Chase experiment. These experiments paved the way for Watson and Crick's discovery of the structure of DNA, and thus the birth of modern genetics and molecular biology.
The experiment was a simple one in concept. Bacteria are able to transfer genetic material through a liquid medium to other bacteria, transforming (giving new genetic characteristics) them. Therefore if bacteria transform when an organic molecule is placed in liquid with them, then that molecule holds genetic information. For the experiment, a bacteria called a Pneumococcus was used. The R strain is harmless, while the S strain causes pneumonia in laboratory mice.
Substances were available to remove various organic compounds from bacteria, and if the remaining organic compounds were still able to cause R strain bacteria to transform then the substances removed couldn't be the carrier of genes. S strain bacteria first had the large cellular structures removed. Then they were treated with protease enzymes, which removed the proteins from the cells before the remainder was placed with R strain bacteria. The R strain bacteria transformed, meaning that proteins didn't carry the genes for causing the disease. Then the remnants of the S strain bacteria were treated with a deoxyribonuclease enzyme which removed the DNA. After this treatment, the R strain bacteria no longer transformed, as evidenced by mice not showing signs of pneumonia when injected with the bacteria. This indicated that DNA was the carrier of genes in cells.
Avery wrote in a letter to his brother, "It's lots of fun to blow bubbles but it's wiser to prick them yourself before someone else tries to."
Nobel laureate Joshua Lederberg stated that Avery and his laboratory provided "the historical platform of modern DNA research" and "betokened the molecular revolution in genetics and biomedical science generally."
Avery, Oswald Avery, Oswald Avery, Oswald Avery, Oswald