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arXiv · 1310.2753

Motility fractionation of bacteria by centrifugation

Claudio Maggi·Alessia Lepore·Jacopo Solari·Alessandro Rizzo·Roberto Di Leonardo
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Abstract

Centrifugation is a widespread laboratory technique used to separate mixtures into fractions characterized by a specific size, weight or density. We demonstrate that centrifugation can be also used to separate swimming cells having different motility. To do this we study self-propelled bacteria under the influence of an external centrifugal field. Using dynamic image correlation spectroscopy we measure the spatially resolved motility of bacteria after centrifugation. A significant gradient in swimming-speeds is observed for increasing centrifugal speeds. Our results can be reproduced by a model that treats bacteria as "hot" colloidal particles having a diffusion coefficient that depends on the swimming speed.

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Claudio Maggi, Alessia Lepore, Jacopo Solari, Alessandro Rizzo, Roberto Di Leonardo. 2013-10-10. Motility fractionation of bacteria by centrifugation. https://doi.org/10.1039/c3sm51223a

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