From 2010.igem.org

Information Processing Overview

Information processing principle of E. lemming. Tumbling / directed movement rates are monitored by image processing algorithms, which are linked to the light-pulse generator. Therefore, E. coli tumbling is induced or suppressed simply by pressing a light switch! This synthetic network enables control of single E. lemming cells.

Although the synthetic network we implemented makes the tumbling frequency of E. coli cells dependent on red and far-red light, the biological part alone is not sufficient to control the swimming direction of E. lemming. Thus, it is complemented by a complex in silico network centered around a controller which guides the cell towards the desired destination.

E. Lemming cells are imaged using microscopy techniques. The resulting images are processed by fast cell detection and cell tracking algorithms, which determine the current movement direction of the chosen bacterium. The desired reference direction is visualized and set by the input of the user, which is translated by the the controller algorithm into series of light pulses (red light and far-red light) . Therefore, by time-dependently changing the tumbling frequency, the cell is forced to swim in a desired direction in real time.