Two-time Nobel Prize winning British biochemist Frederick Sanger died in his sleep on Tuesday at the age of 95. According to the MRC Laboratory of Molecular Biology, which he co-founded in 1962, Sanger was “to many of us, a great friend and a wonderfully modest scientist, and his death is a sad loss.” He is survived by his three children Robin, Peter, and Sally.

“Fred Sanger, double Nobel Laureate and founding member of the LMB in 1962, died on Tuesday 19 November, at the age of 95,” MRC Laboratory said in the statement. “He was an extremely modest and self-effacing man whose contributions have made an extraordinary impact on molecular biology.”

Among his many accomplishments, Dr. Sanger is accredited with pioneering the human genome through methods that identify sequencing in DNA. He received his first Nobel Prize in 1958 for deciphering the structure of proteins by determining how amino acids in insulin are connected. His second Nobel Prize was awarded to him after he helped develop a technique that would decide the building blocks of DNA.

Along with Stanford University's Paul Berg and Harvard University's Walter Gilbert, Dr. Sanger is recognized for discovering the base sequences in nucleic acids. Before opening The Sanger Centre in 1993, now known as The Sanger Institute, Dr. Sanger was quoted saying, “it had better be good.”

Dr. Sanger joined Marie Curie, Linus Pauling, and John Bardeen as one of only four people to win the Nobel Prize twice, the Associated Press reported. Some of his other achievements include becoming a fellow of the Royal Society in 1954, Commander of the Order of the British Empire in 1963, and the Order of Merit in 1986.

“Fred was one of the outstanding scientists of the last century and it is simply impossible to overestimate the impact he has had on modern genetics and molecular biology,” said Deputy Director of the MRC Laboratory of Molecular Biology, Venki Ramakrishnan. “Moreover, by his modest manner and his quiet and determined way of carrying out experiments himself right to the end of his career, he was a superb role model and inspiration for young scientists everywhere.”