Quantitative analysis of bacterial preference for cancer secreting proteins

We present a robust microfluidic platform for stable generation of multiple chemical gradients simultaneously using in situ self-assembly of microparticles in microchannels and show the potential of the proposed system for analysis of bacterial preference for cancer cell secreting proteins. We demonstrate the proof of concept as a preferential chemotaxis assay of bacteria toward multiple chemical sources. Aspartate induces the most preferential chemotaxis over galactose and ribose. The microfluidic device can be easily fabricated with simple and cost effective process based on capillary pressure and evaporation for particle assembly. The assembled particles create uniform porous membranes in microchannels and its porosity can be easily controlled with different size particles. Moreover, the membrane is biocompatible and more robust than hydrogel based porous membranes. The proposed system is expected to be a useful tool for characterization of bacterial responses to various chemical sources, screening of bacterial cells, synthetic biology, and understanding many cellular activities.