ISSN:
1550-7408
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
A two-phase assay was used to assess chemokinesis and gravikinesis of Tetrahymena cells. METHOD: Tetrahymena thermophila cells were cultured without stirring at 36°C in a medium containing proteose peptone, yeast extract, glucose, and MOPS. Growing cells or cells in the stationary phase (1 million cells/ml) were used. Before assay, the cells were diluted 1+1. A semi-microcuvette contained a 1-ml bottom-phase with NycoPrep™ Universal (5% w/v) and MOPS. Carefully, a 1-mL top-phase in the same buffer was layered on top of the bottom-phase. Cells were either in the top- or the bottom-phase. A commercially fed supplement for animals was used as chemoattractant in the phase opposite to the cells (Bioprotein, BP; Norferm, Norway). Changes in cell concentrations were monitored as optical density at 600 nm.RESULTS: (1) cells in top-phase: −BP, 0.0001/30 min;+BP, 0.12/4 min. (2) cells in bottom-phase: top-phase exposed to a stream of nitrogen gas: −BP, 0.07/2 min; +BP 0.05/2 min; top-phase not exposed to a stream of nitrogen gas: −BP, 0.08/2 min; +BP, 0.04/2 min. CONCLUSIONS: The BP proved to be an effective chemoattractant. Gravikinesis was observed with and without the presence of BP. Aerotaxis was not observed. The two-phase assay is a sensitive, reliable, and quick procedure for the assessment of chemokinesis and gravikinesis.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1550-7408.2005.05202003_4_3.x
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