Fluorescence anisotropy selective technique (FAST): A new approach to multicomponent fluorimetric analysis

A new analytical approach to multicomponent florimetric analysis is presented theoretically and is experimentally demonstrated. The new approach, termed fluorescence anisotropy selective technique (FAST), allows one to directly resolve the individual components in complex mixtures on the basis of differences in the rotational diffusion rates of the components. Importantly, unlike steady-state polarization-based approaches, FAST does not require a priori information regarding the number of individual components. By the use of FAST, the individual emission spectra of the two components are extremely similar.