DNA: Secret of Photo 51: On April 25, 1953, James Watson and Francis Crick published their groundbreaking discovery of the double helix structure of DNA. But their crucial breakthrough depended on the pioneering work of another biologist, Rosalind Franklin. 50 years later, NOVA investigates the shocking truth behind one of the greatest scientific discoveries and presents a moving portrait of a brilliant woman in an era of male-dominated science.