ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
When a flagellar filament of a bacterial cell such as Escherichia coli is fixed to a glass surface, the cell body spins alternately clockwise and counterclockwise at speeds of up to 15 Hz. In cells wild type for chemotaxis, reversals occur about once per second. A typical experiment on bacterial behavior involves data collected from as many as 30 such cells over periods of about an hour. A system is described that makes practical detailed analysis of such a large body of data. Microscopic fields, each containing many tethered cells, were recorded on VHS cassettes with a shuttered multiframe video camera. The tapes were played back through hardware that encoded information from successive images of a given cell and passed that information on to a minicomputer. This computer, following instructions provided in an editing session, identified intervals during which the cell was rotating clockwise, rotating counterclockwise, or remained stationary. Output files were generated listing the times at which transitions between these states occurred and the speeds of the cell averaged over successive time periods. This output was then combined with that from other cells and/or processed by various applications programs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1139247
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