DNA sequencing 1953, James Watson and Francis Crick put forward their double-helix model of DNA, based on crystallized X-ray structures being studied by Rosalind Franklin – and without crediting her. According to the model, DNA is composed of two strands of nucleotides coiled around each other, linked together by hydrogen bonds and running in opposite directions. Each strand is composed of four complementary nucleotides – adenine (A), cytosine (C), guanine (G) and thymine (T) – with an A on one strand always paired with T on the other, and C always paired with G. They proposed such a structure allowed each strand
DNA Tower The glass is held in place by a steel armature that is painted blue. The base support of the sculpture is surrounded and protected by a 5' tall circular cherry wood base that is 5'5" in diameter. "DNA Tower" was commissioned to commemorate both the 100th anniversary of the IU School of Medicine (founded 1903) and the 50th anniversary of the discovery of the structure of the DNA molecule (discovered 1953) by 1950 IU alumnus James D. Watson and his colleague Francis Crick. The glass pieces and painted steel armature were fabricated in Chihuly's Seattle studios. On September 23, 2003,