web 2.0 By hartman302 Jan 1, 1928 Griffith Bacteria Experment Jan 1, 1944 Oswald Avery reforms Griffith's experiment Jan 1, 1949 Chargaff's Rule is established Jan 1, 1952 Hershey and Chase confirm DNA is genetic material Jan 1, 1952 Rosalind Franklin uses x-rays to show double helix Jan 2, 1952 DNA shape Jan 1, 1953 Watson and Crick mathematically show DNA helix DNA information page