Fluorescence correlation spectroscopy single molecule studies

The recently developed fluorescence correlation spectroscopy permits studies of molecular associafion in one femtoliter of solufion using a confocal or two-photon microscope. Two lasers are used to excite two fluorophores of different colors, each one on a different type of molecule. Fluorescence of single molecules can be defected, and molecular associations can be detected by changes in the distribution of fhe flucfua-tions in fluorescence intensity caused by Brownian rnohon. A different type of advance is development of compufer programs that analyze chromosomes stained with a mixture of dyes with overlapping spectra and display the result as if each chromosome were painted with a specific color. 

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