Development Of Microchip-based Capillary Electrophoresis System And Study Of Its Applications

A microchip-based capillary electrophoresis system (MECS), which consisted ofa microchip-based electrophoresis analyzer with a 532 nm laser-induced fluorescencedetector and the injection-molding polymethylmethacrylate (PMMA) chips withmulti-channel and the related analytical reagents, was developed. Main features ofthe analyzer included the alternated emission filter in order to select many dyes, 3-Dmicromanipulator controlled by the computer and the channel monitored by chargecoupled device (CCD); two curves of the current vs time for injection channel andseparation channel may be displayed on the computer's screen; the analyzer has highsensitivity, low detection limit, wide linear range of detection, good reproducibilityand stability.The mass-product process, which was to fabricate PMMA plastic chips by aninjection-molding process, was developed. The PMMA chips were mass-product. Anovel sealing method with a mixed organic solvent to seal PMMA chips under lowpress and normal temperature conditions was invented. A novel modification method,which was that modificator was added into the PMMA raw material, was invented.This method is simple, saving-time and high efficiency.The method combining both MCES and methylation-specific PCR had beenapplied to determination of the aberrant methylated p16 gene of cancer patients. Themethod, which will be a new technique for diagnosis of cancer during earlier stage, isfast and highly sensitive. A new method to combine chip-PCR and microchip-basedcapillary electrophoresis was developed and then firstly reported for detection ofSARS virus. This method is rapid, highly sensitive, and is feasible to apply it to earlydetermination of bacteria causing diseases.The interactions between cisplatin, carboplatin, actinomycin D(ActD), bleomcinand 18bp double-stranded DNA were also investigated by MECS. The bindingconstants of actinomycin D and 18bp single-stranded or double-stranded DNA werefirst obtained by non-gel sieving microchip-based capillary electrophoresis. Thebinding stoichiometries were 1:1(single/1ActD molecules) and 1:2(duplex/2 ActDmolecules) calculated from microchip-based electrophoresis and also validated byESI ion-trap mass spectrometry. The microchip capillary electrophoresis is a fast,simple method to study on the strong or weak interactions of small molecularmedicines and nucleic acids.