Sydney Brenner, a South African-born biologist who helped determine the nature of the genetic code and shared a Nobel Prize ion 2002 for developing a tiny transparent worm into a test bed for biological discoveries, died April 5 in Singapore. He was 92.

Dr. Brenner was a central player in the golden age of molecular biology, which extended from the discovery of the structure of DNA in 1953 to the mid-1960s. He then showed in experiments with a roundworm known as C.elegans, how it might be possible to decode the human genome. That work laid the basis for the genomic phase of biology.

Among his many honors, in addition to the Nobel, was the prestigious Lasker Award in medical science, given to him in 1971. For a short time, he had been director of the Cambridge Laboratory of Molecular Biology, but he did not much enjoy working as an administrator, the New York Times said.