Control Software Design Of Microchip Electrophoresis Analysis System For DNA Detection

In recent years, the micro total analysis systems (u-TAS) already becomes an importance forefront research in analytical science, which can quickly and efficiently complete analysis process such as sampling, preprocess, separation and detection in a single chip. To make it possible for electrophoresis system to be miniaturized and integrated with less sample and reagent consumption, microfluidic devices have been used in stead of the traditional capillary in chemical and biochemical analysis. Compared with regular capillary electrophoresis (CE), there are several advantages for microchip electrophoresis such as shorter separation time, small size and high integration, etc.The objective of this thesis is to introduce a Windows Presentation Foundation (WPF) based control software for microchip electrophoresis based on the hardware designed by other members of our team.The control and detection software includes four parts, autofocus on the microchip, temperature control, controllable high voltage power supply, multi-wave length laser-induced fluorescence detection and data analysis. After autofocus, the detection window in the micro-channel can be seen in the center of the microscope’s field of view clearly. When electrophoresis starts under appropriate temperature, CCD will acquire fluorescence spectra images of the fluorescence light emitted in the micro-channel. By fluorescence image processing and analyzing, fluorescent components will be resolved which indicate the information of the detected DNA sample.The workflow of microchip electrophoresis analysis system for DNA detection was detailed in this thesis. And the software requirements were listed clearly as well. Data communications between computer and MSP430 singlechips were established via serial ports, while data communications between computer and microscope and CCD were established by IEEE 1394. The existed C++ program files about microscope and CCD for autofocus were adapted to DLL files which could be used directly in the main program. Driving and data collection were realized through programming for CCD used for spectra collection. Control flows for different modules and important algorithms were also designed and realized in the thesis.Developed with WPF, the software provided a complete system that could control and monitor the entire process of microchip electrophoresis. Users could easily input their instructions and get the outcomings. Data visualization was a highlight in the implementation of the software. Changes of the system temperatures, voltages, currents in the process of electrophoresis, the spectrum data as well as the fluorescence results, all these could be displayed directly in the software in the form of graphs. Besides, the spectrum data and the fluorescence results could be saved to the local file system as.txt files.Multithreaded programming, DLL programming, SDK programming and others programming methods were used flexibly in the thesis, which helped to better meet the mutual requirements in the software system. And the software was realized on an easily-extensible programming framework in which all kinds of controls and elements could be added easily to set up the user interface, accomplish command control and data exchange. The software interface was simple and user-friendly. It could basically meet the needs of microchip electrophoresis.