• Journal of Life Science
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• v.13 no.2
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• pp.163-167
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• 2003

Identification of species within the toxin-producing genus Alexandrium is vital for biotoxin monitoring and mitigation decisions regarding shellfish industry. In particular, the discrimination of resting cysts of only A. tamarense from that of Alexandrium spp. is considerable important to fundamentally monitor and predict this species before vegetative cells occur in the nature. Fluorescent cTAM-F1 DNA probe was responsible to not only binding the activity of the vegetative cells in A. tamarense, but also to the resting cysts, which was treated with methanol after fixation and stained by primuline on the surface The location of fluorescence in cultured vegetative cells and resting cysts was almost at tile bottom of the nucleus. The optimal incubation temperature and time using in situ hybridization were 50-$54^{\circ}C$ and 40-60 min, respectively, to penetrate the DNA probe into cell.

• Journal of Life Science
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• v.12 no.3
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• pp.250-255
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• 2002

Fluorescent species-specific DNA probe (AT1) of toxic dinoflagellate Arexandrium tamarense was tested on several other species, on comparison of binding activity at different preservatives for fixation of the cells, at different culture age and estimation of cell density by light microscope or epifluorescent microscope using whole cell hybridization. Th AT1 probe specifically bound to Alexandrium tamarense, whereas it did not bind to other phytoplankton, in particular Alexandrium catenella, morphologically similar to Alexandrium tamarense, could not react to AT1 probe. When cells were fixed with all three preservatives, labeling cells of Alexandrium tamarense emitted strong fluorescent signal intensity. In addition, regardless culture days, binding activity with AT1 probe was strong. The tell densities estimated by epifluorescent microscope were than those estimated by light microscope. The enumeration and identifying of Arexandriurn tamarense using DNA probe method will be contributed to a new biotoxin monitoring and prediction system in field.