Mode-filtered light capillary electrophoresis (CE) was developed for capillary electrochromatography (CEC) by applying annular columns of different size (250, 320, and 530μm) and a bovine serum albumin (BSA)-modified chiral stationary phase. BSAwas encapsulated on the pretreated surface of an optic fiber and the inner wall of a capillary using sol-gel technique with a resultant larger active stationary phase area. The coating was examined by atomic force microscopy (AFM) and Fourier transform infrared (FT-IR). The separation of DL-tryptophan (10mM) was investigated under different voltage/current conditions.

A novel mode-filtered light detection method is described in which an unjacketed optical fiber is inserted into a transparent capillary tube and three or more detection channels are set on the capillary side for different distances from the port of the fiber. This new method is the basis of synchronization of separation and analysis, with which a modern multidimensional analysis apparatus will be constructed. For samples of different concentration, the more close to the laser incidence port of the fiber the detector has been set up, the greater the change of the intensity profile of mode-filtered light (IF) that is obtained. Vice versa, if a parameter = I0/In is established and, instead of a mode-filtered light signal, the reversed alteration trend of is found in comparison with the alteration trend of IF, the reason is that the background rapidly lowers with the increasing distance to the laser incidence port of the fiber; moreover, the mode-filtered light signal decreases slowly with it. With the present method and apparatus, glucose and glycerol have been determined, with good reproducibility and stability and a small sample volume. Furthermore, a real sample of glucose injection is measured for a detection volume of 5 L, and an acceptable result is observed.

An optical fiber-chromatographic sensor, aiming at simultaneous and selective response to multiple components following a chromatographic separation, is described. We report an improved approach for immobilization of octadecyl (C18) and methyl (C1) moieties as stationary phase on an optical fiber suitable as a sensing phase for organic solutes. By this approach, the stability and lifetime of the sensing layer as well as the detectability and retention behavior of the chromatographic sensor could be improved. Infrared spectroscopy was employed to confirm the presence of C18 and C1 moieties on the modified surface of the optical fiber. The chromatographic sensor was applied, with good sensitivity and chemical selectivity, to the simultaneous separation and detection of bromobenzene and toluene, using water as the mobile phase.

Nucleic acids lig ation is a vital process in the repair, replication and recombination of nucleic acids. Traditionally, it is assayed by denatured gel electrophoresis and autoradiography, which are not sensitive, and are complex and discontinuous. Here we report a new approach for ligation monitoring using molecular beacon DNA probes. The molecular beacon, designed in such a way that its sequence is complementary with the product of the ligation process, is used to monitor the nucleic acid ligation in a homogeneous solution and in real-time. Our method is fast and simple. We are able to study nucleic acids ligation kinetics conveniently and to determine the activity of DNA ligase accurately. We have studied different factors that influence DNA ligation catalyzed by T4 DNA ligase. The major 1advantages of our method are its ultrasensitivity, excellent specificity, convenience and real-time monitoring in homogeneous solution. This method will be widely useful for studying nucleic acids ligation process and other nucleic acid interactions.

A novel method has been developed to monitor the nucleic acids ligation process. Molecular beacon was employed here to convert the ligation information into fluorescence signal quickly and quantitatively. This method provides effective and original approach to researching the dynamic ligation process and the interactions between nucleic acids and ligase. An analytical method for T4 DNA ligase based on this way has been built up with a linear detection range from 2.3