alte Seiten

Aim

Analyzing single cells to overcome limitations of averaged results from cell population research. The single cell workstation at the ISAS Dortmund (left), a close up of the cell handling chip equipped with the appropriate microfluidics (middle), and a close up of the bare chip (right).

Function of the microfluidic chip

The microfluidic chip allows the selection of a single cell by a dielectrophoretic (DEP) field cage and long term contact less capture in a constant micro flow that enables constant supply of nutrients. The field cage is made of eight electrodes on the top and bottom of the microfluidic channel (top view of four electrodes). Operation of the field cage: Yeast cells (green) are passing the cage (left). The operational field cage traps cells and disables following cells to pass (middle). Adjusting cell loading concentration allows the trapping of a single S. cerevisiae cell in a constant medium flow (right).

Growth of single cells

We used the microfluidic chip for analysis of pseudo hyphal growth of diploid S. cerevisiae under nitrogen limitations starting from a single yeast cell (left). The cellular growth rate was with 0.42 1/h highly similar to experiments in shake flasks during batch cultivations, suggesting that no cellular stress was introduced by the experimental conditions used. These results show that we have developed a single cell bioreactor for highly reproducible microbial experiments.


Pictures (from the left): Single yeast cell. Pseudohyphal growth during a period of three hours.