The Observation of Bacteria and Yeast through Microfluidic Devices

The microbes are intimately to our lives, therefore the researches of behaviors of microbes such as growth, division, anastomosis, transfection, transformation, death etc. are very important. Traditional methods such as freeze-etching method, can only find different growing periods through different cells so there is still no definite evidence for the existence of some biological activities. This would destroy a biological sample as well, so that later experiments can not be carried over smoothly. The effects of microscale heterogeneities cannot be replicated by conventional experimental techniques as well. We have recently incorporated PDMS-based valves and pumps for the analysis of single nonadherent yeast and bacteria cells. Optical trapping facilitated and ensured the encapsulation of single cells within the individual microdroplets. In this way, we have photographed the process of division of Saccharomyces sp. , and Bacillus megaterium.