| Summary: | 碩士 === 國立臺灣大學 === 昆蟲學研究所 === 93 === The red imported fire ant (RIFA, Solenopsis invicta Buren) is one of the most destructive imported insect pests in Taiwan. They are not only invaders that bring serious ecological problems, but also aggressive medical pests that cause various human damages and symptoms such as the formation of characteristic sterile pustules, urticaria, edema, dermal necrosis, and even anaphylactic shock and death in rare cases. Approximately 270 species of ants were discovered in Taiwan, and some are very similar to S. invicta in their morphological characters. For example, the tropical fire ant (Solenopsis geminata) and several members of subfamily Myrmicinae such as Monomorium, Pheidole and Pheidologeton are not easy to be directly and quickly distinguished each other according to their morphology. For rapid and accurate identification of S. invicta to avoid people’s panic, monoclonal antibodies against the specific venom in the venomous gland of S. invicta were developed through the hybridoma technology. S. invicta and several ant species were collected for the venom analysis by SDS-PAGE (SDS-polyacrylamide gel electrophoresis), and the results demonstrated that the protein pattern in SDS-PAGE of S. invicta is different from the others. It indicated that the venom proteins are different among S. invicta as well as the other ant species. Four proteins were isolated and identified from venom. One of them is located in 13 kDa, the others are near around 24 kDa. The venom was used to immunize the mouse to develop monoclonal antibody. In the beginning, the polyclonal antiserum against venom of S. invicta showed positive to S. invicta and S. geminata, and negative to the other ant species. And in later totally 30 hybridoma cell lines have been selected to produce specific antibodies against S. invicta. A cell line named Rf-E7 showing the best specificity and sensitivity was selected for the mass-production of monoclonal antibodies. Furthermore, the monoclonal antibody Rf-E7 was proven to be able to accurately differentiate S. invicta from S. geminata. Both ascetic fluid and purified IgG of Rf-E7 showed the good specificity and sensitivity in the ELISA tests with 105 diluted antibodies. Dried, dead bodies and the samples treated with insecticides as well as preservative solutions obtained the slightly lower ELISA value than fresh samples. However, their ELISA values were still useful for identification of S. invicta. In the temperature experiment, the ELISA tests did not show apparently different results among different S. invicta populations residing in 15, 25, or 35℃. It revealed that alteration of temperature would not affect the quantity of RIFA venom. Based on the results in this thesis, the developed monoclonal antibody Rf-E7 has been proven to be an excellent probe for rapid identification of S. invicta. This antibody will be further dedicated to the preparation of the colloidal gold-labeled antibody strip that provides a more rapid and simple detection of S. invicta without any analytic instrument. People can identify whether their ant samples are S. invicta or not by themselves at home, which can reduce public panic for S. invicta.
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