Drop chemostats on a chip

The adaptation process of biological system to novel challenge has a lot of variability. To investigate the spectrum of possible adaptation trajectories requires large ensemble of identical twin population. To address this challenge, we are developing a drop-based microfluidic device with hundreds of chemostats on a single chip. The chemostat is a continuous-culture apparatus that enables growth of cells in a well-controlled environment. The controlled conditions of the chemostat enable the measurement of population response to specific factor by varying only one environmental factor at a time. In the drop microfluidic approach, the chemostat vessel is ~1µL media drop surrounded by inert oil. Every population in every drop is an independent chemostat population. Each chemostat droplet is continuously diluted with fresh media. The flow of the chemostat drop insure the mixing of nutrient and suspension of the cells. The surrounding oil reduce the fouling of cells to the channel walls. The measurements can be done on the whole chemostat drop or only on the subtracted fraction. The subtracted fraction from the chemostat can be used to monitor the cells and environment in the drop using variety of distractive assays without interfering the chemostat experiment.