Dual-Color Confocal Fluorescence Spectroscopy and its Application in Biotechnology. Fluorescence Correlation Spectroscopy. Berlin: Springer Berlin Heidelberg; 2001. pp. 187-203. [DOI: 10.1007/978-3-642-59542-4_9]

Review fluorescence correlation spectroscopy for probing the kinetics and mechanisms of DNA hairpin formation

This article reviews the application of fluorescence correlation spectroscopy (FCS) and related techniques to the study of nucleic acid hairpin conformational fluctuations in free aqueous solutions. Complimentary results obtained using laser-induced temperature jump spectroscopy, single-molecule fluorescence spectroscopy, optical trapping, and biophysical theory are also discussed. The studies cited reveal that DNA and RNA hairpin folding occurs by way of a complicated reaction mechanism involving long- and short-lived reaction intermediates. Reactions occurring on the subnanoseconds to seconds time scale have been observed, pointing out the need for experimental techniques capable of probing a broad range of reaction times in the study of such complex, multistate reactions.

Fluorescence correlation spectroscopy for the detection and study of single molecules in biology

The recent development of single molecule detection techniques has opened new horizons for the study of individual macromolecules under physiological conditions. Conformational subpopulations, internal dynamics and activity of single biomolecules, parameters that have so far been hidden in large ensemble averages, are now being unveiled. Herein, we review a particular attractive solution-based single molecule technique, fluorescence correlation spectroscopy (FCS). This time-averaging fluctuation analysis which is usually performed in Confocal setups combines maximum sensitivity with high statistical confidence. FCS has proven to be a very versatile and powerful tool for detection and temporal investigation of biomolecules at ultralow concentrations on surfaces, in solution, and in living cells. The introduction of dual-color cross-correlation and two-photon excitation in FCS experiments is currently increasing the number of promising applications of FCS to biological research.