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.
Dr. Lerman went to Cambridge, England, to work in the lab of Sydney Brenner and Francis Crick, A few years earlier, Crick and James Watson were there when they announced they had discovered DNA’s double helix structure.
With Brenner and Crick, Dr. Lerman continued his intercalation research, which helped lay the groundwork for the discovery of the triplet code, the idea that genetic sequences occur in threes.
When the results of Dr. Lerman’s intercalation studies were published, they prompted a new round of experiments that furthered the understanding of DNA.
Dr. Lerman’s third major contribution to the field of molecular biology was creating a process known as denaturing gradient gel electrophoresis to separate DNA fragments. The process helps provide information about mutations that lead to genetic diseases, and is widely used to determine biodiversity in populations of microorganisms.
The latter experiments were done at the University at Albany, State University of New York, where he worked after a stint at Vanderbilt.
In the 1970s, Dr. Lerman accepted an invitation to work at the Genetics Institute in Boston. But he soon yearned for the freedoms of the university laboratory system, and Fox had room to spare in his MIT lab, so the two ran separate labs out of a shared space. “I invited him to come and use it,” Fox said. “I was so confident in the kind of work he did, it didn’t matter what he was working on.”
Dr. Lerman, Fox added, “really understood DNA.”
As a teenager in Pittsburgh, where he was born, Leonard Solomon Lerman won a science radio show contest and was awarded a scholarship to what is now Carnegie Mellon University. Beginning college at 16, he graduated with a bachelor’s degree in just five semesters.
Dr. Lerman married Claire Lindegren in 1952 and they had three children. His marriage to her ended in divorce, as did his marriage to Elizabeth Taylor.
Graduate students who worked in Dr. Lerman’s laboratories knew that he would provide them with a moderate amount of guidance, but that he expected them to work mostly independently. Among his students were Sidney Altman, who shared the Nobel Prize in chemistry in 1989, and Maniatis.
“To a certain extent, Leonard would make it into a game,” Maniatis said. “He always knew the answer and he would never tell you. He would force you to think on your own.”
Maniatis added that “the thing I got from him more than anything was rigorous, critical thinking and independence.”
At home, Dr. Lerman often applied a scientific approach to solving everyday problems. His first wife didn’t like listening to TV commercials, so he designed and built a remote control well before such a device could be purchased in stores. When water drenched a houseguest’s plaster cast, he came up with a vacuum system that dried it within minutes.
“He was very creative, very original,” said Dr. Lerman’s longtime partner, Lisa Steiner. “He would always invent something, he would always do something new.”
Dr. Lerman “was soft-spoken, but he had a very wry sense of humor,” said Steiner, who added that he “was quiet and unassuming. He never blew his own horn.”
A service has been held for Dr. Lerman, who, in addition to Steiner, leaves two daughters, Averil of Anchorage, and Lisa of Bethesda, Md.; a son, Alexander of Chappaqua, N.Y.; and seven grandchildren.
Dr. Lerman’s mind seemed never to leave the laboratory.
In the midst of a conversation “his mind would often drift,” Maniatis said. “He was a deeply inward intellectual and really thought very deeply about problems.”Emma Stickgold can be reached at firstname.lastname@example.org.