Tracking passive particles in baths of E.coli

With the aim to understand the dynamics of passive colloids surrounded by active particles. Here, we study the Brownian movement of varying sizes of latex particles in a bath of E. coli bacteria in comparison to water. Vials were mixed with latex particles, luria broth, and E. Coli. 

Using a single-particle tracking method, we calculated the mean square displacement based on observations of the trajectories of individual particles. Our results for the mixture of latex particles in a bath of E. coli indicate super diffusion in short times and normal diffusion in long times.  Determination of diffusion coefficients from the correlation of positions of the particles is discussed.