On-chip microcultivation chamber for swimming cells using visualized poly(dimethylsiloxane) valves

We have developed a new type of on-chip microcultivation chamber made of poly(dimethylsiloxane) (PDMS) for long-term cultivation of swimming cells. The advantages of this chamber are that (1) the microfluidic channel width of the valve can be controlled according to air pressure while monitoring the microscopic image of the channel width, and that (2) a simple single-step procedure is required for the fabrication of the valve structure and microfluidic pathway. Using this chamber, we can control the passage of swimming Chlamydomonas cells, through the channel while visualizing the opening and closing of the valve as the medium buffer passes any time. Thus the long-term observation of the behavior of a particular single cell is accomplished.