Using tools he often had made himself, Leonard Lerman took great care in making precise measurements during experiments he performed to further the understanding of DNA.

A simple way to state it is that he was a deeply quantitative man, said Tom Maniatis, chairman of the biochemistry and molecular biophysics department at Columbia University, who had worked with Dr. Lerman as a graduate student at Vanderbilt University.

Discoveries he made about what can unwind the strands of DNA, and other research throughout his career, helped Dr. Lerman become a key figure in the field of molecular biology.

He was both a deep and brilliant man, and also a clever man, in the sense that he always had great ideas and techniques, Maniatis said.

Dr. Lerman, formerly a senior lecturer at the Massachusetts Institute of Technology, died Sept. 19 in his Cambridge home of a chronic neurological disease. He was 87.

He did lots of things that served for the increased understanding of the structure of DNA and the things that interacted with DNA, said Maurice Fox, a professor emeritus of molecular biology at MIT.

Dr. Lerman, Maniatis said, saw the world through mathematics and could use mathematical and physical properties of molecules to predict what would occur.

As a graduate student at the California Institute of Technology, Dr. Lerman worked with Linus Pauling, who in 1954 was awarded the Nobel Prize for chemistry and has often been referred to as one of the founders of molecular biology.

Dr. Lerman set out to prove his hunch that antibodies have two binding sites to bond with antigens, which are any foreign substances that prompt an immune response. After achieving that goal, he graduated from Cal Tech with a doctorate in chemistry in 1950 and went on to join the faculty of the University of Colorado.

The 1950s were an active time for DNA research. Dr. Lerman was determined to find out more about chemicals that attach to DNA strands and make them unwind, often causing mutations. The way certain chemicals attach to the strands is called intercalation, and it occurs between adjacent base pairs in double-stranded DNA.

See more here:
Leonard Lerman, 87; senior lecturer at MIT researched DNA