A Microfluidic Culturing System for Observation of Free-Floating Microorganisms Available to Purchase

We observed the effect of the ethanol toxicity on individual cells of Botryococcus braunii (B. braunii) in microchannel environment. For continuous observation of B. braunii in microchannel environment, a microfluidic device which has a specific channel structure was developed. By using the channel structure, microorganisms were sorted by their size and captured on the corresponding area in the channel. In the experiment, suspension of B. braunii with DAPI was injected into the device for the cell capturing in the experiment. Following the cell capturing, ethanol with DAPI 0.5% was injected into the channel for 60 minutes. Damaged cells were confirmed by their deformation and the fluorescence of DAPI. The strong fluorescence of DAPI was confirmed after 20 minutes. On the other hand, the fluorescence of the chloroplast became weak in contrast to the fluorescence of DAPI. We successfully confirmed the time condition of exposing B. braunii to ethanol in the micro channel.