Karle, Jerome (1918-) is an American chemist and crystallographer who, in 1985, shared the Nobel Prize in chemistry with American chemist Herbert Aaron Hauptman for their development of the “direct method” of determining the structure of a crystal.

Although his family was artistically and musically inclined, Karle himself was naturally drawn to science. Karle attended the City College of New York, where Herbert Aaron Hauptman was a fellow student. Karle graduated with a B.S. degree in 1937. He then went to Harvard University, where he received a master's degree in biology in 1938. While doing graduate work at the University of Michigan, he met another Ph.D. degree candidate in chemistry, Isabella Lugoski, and they married in 1942. Karle received his Ph.D. degree in chemistry in 1944.

After a year with the Manhattan Project at the University of Chicago, Karle and Isabella returned to Michigan where he began work on a project for the U.S. Naval Research Laboratory. In 1946, the couple relocated to the Naval Research Laboratory in Washington, D.C., and in 1968, Karle was named chief scientist of the newly instituted Laboratory for the Structure of Matter there.

In 1947, Hauptman became a researcher at the Naval Research Laboratory, and he and Karle worked on devising a mathematical equation by which the three-dimensional molecular structure of any crystal could be deduced.

Karle and Hauptman studied X-ray crystallography, in which a beam of X rays is fired at a crystalline material. The X rays are scattered from the rows of regularly spaced atoms in the crystal and captured by a photographic film. The pattern created by the diffraction of these rays can then be analyzed to determine the material's structure.

Karle and Hauptman solved problems in the mathematical analysis of X-ray diffraction patterns, developing what were called “direct methods” for crystal structure analysis. Until Karle and Hauptman arrived at their solution, methods used to interpret these patterns were time-consuming and not very reliable. Isabella Karle, who had set up experimental facilities in the lab, developed a procedure for the direct method in using practical applications. It became known as the symbolic addition procedure, which greatly sped up the ability to analyze molecules accurately. Her method is the basis of advanced X-ray crystallography today and is used worldwide.

This direct method of determining molecular structure, however, did not immediately find wide acceptance. The complexity of the mathematics necessary to solve these structures was intimidating to many chemists and the method's practical uses were not at first readily apparent. Their method has led to the ability to identify the structures of thousands of biological molecules, including those of various hormones, antibiotics, and vitamins. Karle and Hauptman's pioneering work received recognition through their 1985 Nobel Prize in chemistry.

Karle continued his investigations into molecular structure through the 1970's and, among many other achievements, in 1980 published his multi-wavelength anomalous dispersion technique, which opened the door to further advances in the field of macromolecular structure analysis. He has been a visiting lecturer at locations throughout the world, has won dozens of awards, and received many honorary degrees from prestigious universities throughout the country.

Since winning the Nobel Prize, Karle has also dedicated much time and energy toward working with students and with organizations whose aim is the improvement of the quality of life for all people.