Tanaka, Koichi, 1959–, Japanese engineer, B.S. Tohoku Univ., 1983. He has been a researcher at Shimadzu Corporation in Kyoto, Japan, since 1983. Tanaka shared the 2002 Nobel Prize in Chemistry with John Fenn and Kurt Wüthrich for the development of methods for identifying and analyzing the structure of biological macromolecules. Before their work, mass spectroscopy could be used to analyze only fairly small molecules. Tanaka is credited with pioneering matrix-assisted laser desorption/ionization (MALDI), a mass-spectroscopy technique in which proxy substances called matrixes are used to absorb laser energy and promote the ion formation of large molecules, which are otherwise prone to thermal degradation during analysis.