To determine flow properties, namely, the velocity and angle of the flow in microstructured channels, an experimental realization based on fluorescence correlation spectroscopy is described. For this purpose, two micrometer-sized spatially separated volume elements have been created. The cross-correlation signal from these has been recorded and evaluated mathematically. In addition to previous results, two-beam cross-correlation allows for fast and easy determination of even small (down to 200 μm/s) flow velocities, as well as simultaneous measurement of diffusion properties of single dye molecules within a rather short detection time of 5-100 s and an error rate of less than 20%. The spatial flow resolution is around 1-2 μm, limited by the diameter of the volume element. Furthermore, vectorial flow data can be obtained and evaluated. A discussion of the theoretical background and an experimental verification of the theoretical results is performed. The feasibility of fast and easy data processing is shown if the flow time is the only desired information. Possible applications of this precise and simple method are the determination of transportation effects within artificial microstructures for CE and HPLC, fast chemical kinetics, and high-throughput screening.

A method is described that demonstrates a new technique for rapid and high‐throughput single molecule sequencing. This sequencing technique is based on the successive enzymatic degradation of fluorescently labeled single DNA molecules, and the detection and identification of the released monomer molecules according to their sequential order in a microstructured channel. The detection technique is evolved from confocal fluorescence microscopy, with two different laser sources to excite the individual mononucleotides that are either labeled with tetramethylrhodamine (TMR) or Cyanine5 (Cy5). The handling of DNA which is immobilized on carrier beads, and the detection of the cleaved monomers is performed in optically transparent and biochemically inert microstructures (glass or PMMA) with detection channels of 7 μ × 10 μm. The projected rate of sequencing is ≈100 bases min−1, dependent solely on the rate of the enzymatic DNA cleavage.

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