A METHOD FOR MEASURING BACTERIAL CHEMOTAXIS PARAMETERS IN A MICROCAPILLARY

A new meth od was developed wh ich enables chemotaxis parameters to be measured at a single-cell level inside a capillary for the first time . The chemotaxis chamber consists of two reservoirs communicating thro ugh a capillary tube 50 mu m in diameter. Chemotaxis parameters are me asured inside the capillary using image analysis, after a nearly linea r attractant concentration gradient has been generated along the capil lary by diffusion. Compared to previously published techniques, this m ethod provides a well-characterized chemoattractant concentration prof ile in addition to allowing single-cell parameters to be measured insi de a fine capillary. This procedure was used to measure the single-cel l chemotaxis parameters for Escherichia coliK12, and the results are c ompared to published data on single E. coli cells chemotaxing in bulk. (C) 1996 John Wiley & Sons, Inc.