He won the Nobel Prize in Physiology or Medicine for the test-tube synthesis of DNA and shared the award with Dr Severo Ochoa, who in turn was honoured for the synthesis of RNA. In the early 1950s, James Watson and Francis Crick had put forward a theory of how DNA is replicated but it was Kornberg who discovered the actual chemical mechanism by which DNA is constructed in the cell.

"There have got to be tens of thousands of people around the world whose eyes are tearing up with the news that he's gone," said Dr Paul Berg, winner of the 1980 Nobel Prize in Chemistry for his work with recombinant DNA.

"He was an extraordinary scientist. His accomplishments might be called legendary. The style in which he did his science was inspirational."

Kornberg often referred to his career as a "love affair with enzymes", and together with Ochoa, they discovered new enzymes that create the building blocks of DNA and RNA and also the enzyme Kornberg called DNA polymerase that assembles those building blocks. This laid the foundation upon which recombinant DNA and genetic engineering were built and so provided the basis for many drugs currently used to treat diseases such as cancer and viral infections.

"Dr. Kornberg was one of the most distinguished and remarkable scientists in American medicine," said Philip Pizzo, MD, dean of the Stanford University School of Medicine, where Kornberg was professor emeritus of biochemistry.

"His towering contributions have continued virtually up until the time of his death. Without doubt, his legacy will certainly live on for many, many generations to come."

His son, Dr Roger Kornberg also won the Nobel Prize 46 years after his father. This time, the award was in chemistry, but it was, again related to DNA. Roger Kornberg was the first to create a molecular-level picture of how DNA copies itself (transcription) in eukaryote organisms.

Arthur Kornberg is survived by his wife, Carolyn Frey Dixon Kornberg, three sons and eight grandchildren.