[Electrophoretic properties of a population of Escherichia coli cells studied by microelectrophoresis]

The technique of microelectrophoresis was used to measure the rate of E. coli cell motility under the action of a constant electric field, and the electrokinetic potential (xi-potential) was calculated from the experimental data. As was shown by analysing the results for a sample from 100 cells, the property varied within a wide range which exceeded several times the error of a single measurement. This variation was associated with the different electrosurface properties of microbial cell groups and is characteristic of a cell population. The empirical distribution of the parameter was shown to be consistent with the normal law. The results of determining the electrokinetic potential may statistically be processed with a computer, and the profile of an experimental curve will characterize the physico-chemical state of cells.