SAN FRANCISCO, Oct. 5 – You’ve heard of the nuclear family. But how about the deoxyribonucleic family? Thirty-seven years after Arthur Kornberg won the Nobel Prize in medicine, his eldest son, Roger, took home this year’s prize in chemistry, receiving the call from Stockholm, Sweden, on Tuesday, Oct. 3. Not only are both Kornbergs biochemists, they also both work for Stanford Medical School. This is, amazingly, the sixth instance of a Nobel being awarded to the son of a previous winner. “It was a family of science. My mother, who unfortunately passed away about 20 years ago, worked in the lab as a biochemist with my father. So biochemistry was a dinner table conversation,” recalled Roger Kornberg’s younger brother, Tom, himself a biochemist at U.C. San Francisco. The third Kornberg brother, Ken, is not a scientist but an architect — though he specializes in designing laboratories. “Roger was uniquely focused on science from the time he was very, very young,” Tom Kornberg said. “He had no other ambition other than to be a scientist. He is notable even today for his single-minded dedication among scientists. His tenacity and determination is remarkable.” Arthur Kornberg — who still has his own lab at Stanford Medical School at age 88 — grew up in an Orthodox Brooklyn household where Yiddish was the first language. His future wife, Sylvy Levy, also grew up Orthodox, but the couple raised their children in a fairly secular environment. Still, the family had a strong Jewish and pro-Israel identity and Roger Kornberg is a consistent donor to the S.F.-based Jewish Community Federation. Roger married an Israeli scientist, Yahli Lorch, a Stanford professor of structural biology, and the couple lives almost half the year in their Jerusalem apartment, where Roger leads his research team remotely via the Internet. He returned from Israel just before winning the prize, having delivered a lecture at the Hebrew University of Jerusalem on Sept. 26, where he has been a visiting professor for the past 20 years. Roger Kornberg was honored for his study of transcription, a process of DNA replication. Instead of creating proteins directly from DNA, the DNA recreates itself in the form of RNA, which traverses from the nucleus to other cell locations where it kicks off protein production. Kornberg has studied the vast intricacies of transcription since the early 1970s, fitting together the more than 30,000 atoms present in RNA polymerase, the enzyme that allows DNA to remake itself into RNA. Kornberg’s lab created the world’s first images of polymerase in action, enabling the zipper-like undoing and redoing of the double helix. “We were astonished by the intricacy of the complex, the elegance of the architecture, and the way that such an extraordinary machine evolved to accomplish these important purposes,” Kornberg told a Stanford publication of the images he and his colleagues created. “RNA polymerase gives a voice to genetic information that, on its own, is silent.” That voice doesn’t automatically make itself heard. Transcription occurs on a selective basis, and transcription among a cell’s tens of thousands of genes decrees whether it develops into a liver cell, a stem cell or a neuron. It also determines whether it develops healthily or cancerously. Creating the groundbreaking images of RNA polymerase was a backbreaking task requiring an expertise in an esoteric field combining chemistry, biology and physics called crystallography — the same technique, incidentally, that Francis Crick and James Watson utilized to discover the double helix. To greatly simplify the work of Kornberg’s lab, a concentrated solution of a molecule was evaporated until all that was left behind were highly structured crystals reminiscent of the salt deposits left behind by vaporized seawater. Via intensely bright X-rays, scientists were then able to identify the exact location of individual atoms and generate a computer model of the molecule. Kornberg’s tenacious feat of illustrating the 10 subunits of RNA polymerase in action was a task two decades in the making. “It was a technical tour de force that took about 20 years of work to accomplish,” professor Joseph Puglisi, chair of the department of structural biology at the Stanford School of Medicine, told a Stanford publication. “Like other great scientists, Roger doesn’t quit. He’s stubborn. A lot of scientists would have given up after five years.” Each Nobel Prize includes a check for $1.4 million, a diploma and a medal, which will be awarded by Sweden’s King Carl XVI Gustaf at a ceremony in Stockholm on Dec. 10.