Manfred Eigen

Dual-Color Confocal Fluorescence Spectroscopy and its Application in Biotechnology

In recent years, fluorescence correlation spectroscopy (FCS) has become an attractive analytical tool for the investigation of biomolecular processes at the single molecular level. This method was invented in the early 1970s by groups at Cornell University, Ithaca, N.Y. [9.1,9.2], and at the Karolinska Institute, Stockholm [9.3,9.4]. During the 1990s, modern confocal optics, new dyes as efficient fluorescent probes, sensitive photon detectors, and fast data processing tools have been introduced, mainly by Rigler and Eigen [9.5,9.6]. Due to these improvements, FCS permits the observation of the dynamics of single molecules in real time while they pass an open volume element of less than a femtoliter, i.e. the size of a common bacterial cell. Nowadays, FCS has found its way into several laboratories and companies all over the world as a tool for basic research as well as for industrial applications such as drug screening.