Fluorescence correlation spectroscopy for ultrasensitive DNA analysis in continuous flow capillary electrophoresis

Continuous flow capillary electrophoresis (CFCE) is non-separations based analytical technique based on the free solution electrophoretic mobility of biological molecules such as DNA, RNA, peptides, and proteins. The electrophoretic mobilities and translational diffusion constants of the analyte molecules are determined using single molecule detection methods, including fluorescence correlation spectroscopy (FCS). CFCE is used to resolve multiple components in a mixture of analytes, measure electrophoretic mobility shifts due to binding interactions, and study the hydrodynamic and electrostatic properties of biological molecules in solution. Often this information is obtained with greater speed and sensitivity than conventational separations-based capillary-zone electrophoresis. This paper will focus on the application of two-beam fluorescence cross-correlation spectroscopy as a versatile detection method for CFCE and explore several applications to the study of the solution properties of single-stranded DNA.