| Microinjection is often used in Gene Introduction in the Biological Engineering. Through it, the exterior genes are often effectively introduced into the chromosome of the embryonic period's receptors, and then will be integrated so that when the receptorsomatic and germ cells grow up, they will have a good expression. Therefore, microinjection is attracting more and more attention of the researchers in the biological fields. By far, about 80% or more transgenic animals are constructed through microinjection.The technique of microinjection is significant to embryo's development. For example, the different volume of microinjection will have direct effect on the in vitro survival rate of the embryos and even the successful rate of the transgenic animals. There are some shortcomings in the microinjection whose volume is controlled by manual, such as less effective, less precise and more sensitive to artificial factors, etc. All these keep the microinjection operation from being more popular and applicable.At present some volume controllers with high-qualities which can argely decrease the manual work of the microinjection volume control are put up with by several international biological companies. With the new devices, microinjection is turned into a half-automatic one. However, these devices are too expensive to many domestic research associations and societies of the gene engineering. On the purpose of catching up with the advanced level of the world, and developing microinjection devices of ourselves to promote the Chinese gene engineering, this paper is dedicated to the design and fabrication of the microinjection volume controller and the research on the detection of microinjection volume by micro-vision, based on looking into the advanced products mentioned above and researches on the dynamical characteristics of the DNA micro-fluid from both theoretical and experimental aspects.Several research works are done in this paper according to the topics mentioned above:1. Looking up a lot of documents and materials about the microinjection technique, devices and the controlling technology of micro-fluid from outside and inside the country. Based on the theoretical researches about the DNA micro-fluid's dynamical characteristics, the controlling model of the microinjection volume is set up, and the experimental research on it is also done.2. Planning and Designing a microinjection controller on its structure, parameters and circuit tolerance analysis, etc. aspects. Based on the primitive electrical microinjection volume controller driven by air-pressure, an improved one with the pressure-keeping function is fabricated. The new controller prevents the DNA-fluid from drawing-back by providing a keeping-pressure to it before or after the microinjection. That often occurred while with the primitive one.3. The research on the fluid of micro-scale has an applicable perspective, so it has been the focus of the fluidics experts and engineers in recent years. A new plan of thermal controller is presented in this paper, based on the research on the micro-fluid's surface tension. The Marangoni effect is used to adjust the surface tension of the DNA fluid in order to drive it moving from the warmer end to the cooler end. The following experiment's results show that, as the temperature increasing, the viscosity of the DNA fluid is decreasing, as well as the resistance to its movement, so that the dead area of the controlling is narrowed and the controller is improved.4. Microinjection is a delicate and precise operation suffered from the artificial factors of the operators (such as healthy condition, mood at the time, etc), and also the surrounding conditions. So the manual work is inevitably replaced with an automatic one in this kind of devices. On the basis of the characteristics of the cell micro-images, three image processing methods are used separately in cell images' quick recognition and feature's snapping to get the fast detection of the injection volume by vision.
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