Automatic Micro Manipulation System for Cell Manipulation
Keyword: Piezo Manipulator, Micro Manipulation, Micro Injection, In Vitro Fertilization
Introduction
Recently, in biotechnological research on mammals and artificial fertility treatment, such as ICSI (intracytoplasmic sperm injection) method, it is necessary to do minute operation precisely by micrometer order. A minute work device (micro manipulator) is used for the work to add physical operation (micro manipulation) to gene, nucleus, or embryo (fertilized egg). However, this operation really depends on operator's skill. Therefore, the efficiency of this work is very low, and the automation of this operation, which does not depend on the skill of operators, is strongly demanded.
In this study, we have developed automatic micro manipulator system for cell manipulation by utilizing mechatronic technologies such as piezo impact drive mechanism, precise positioning, and image processing.
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| Whole system image |
Minute work part |
Microinjection using piezo impact drive mechanism
It is necessary to insert a micro pipette into the cytoplasm in case of sperm injection or DNA transplantation. By using conventional hydraulic manipulators, it has been found that the cell largely deformed due to the cell membrane elasticity. This deformation even can destroy the nucleus. Here, we applied piezo impact drive mechanism, which utilizes rapid deformation of piezoelectric element, to realize smooth insertion of the micro pipette into the cytoplasm without deformation. This mechanism had already been commercialized and being used in many institutes.
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Micro injection using micro manipulator with piezo impact drive mechanism
| Micro injection using hydraulic micro manipulator
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Egg cell automatic search mechanism using image processing
Usually, there are dozens of egg cells put in one medium drop on the dish. It has been a big burden for the operator to search them one by one. In this research, we have developed a device, which can process image from the microscope with a CCD camera and can pick up egg automatically by using XY positioning stage.
Image processing screen
Reference
[1] Kudoh, Gotoh, Satoh, Yamagata, Furutani, Higuchi. Development of Micro Manipulator Using Piezoelectric Element. Journal of Mammalian Ova Research Vol. 7 No. 1 1990, pp. 7-12 (in Japanese)