Induction of sustained glycolytic oscillations in single yeast cells using microfluidics and optical tweezers

摘要

Yeast glycolytic oscillations have been studied since the 1950s in cell free extracts and in intact cells. Until recently,sustained oscillations have only been observed in intact cells at the population level. The aim of this study was toinvestigate sustained glycolytic oscillations in single cells.Optical tweezers were used to position yeast cells in arrays with variable cell density in the junction of a microfluidicflow chamber. The microfluidic flow chambers were fabricated using soft lithography and the flow rates in the differentinlet channels were individually controlled by syringe pumps. Due to the low Reynolds number, the solutions mixed bydiffusion only. The environment in the junction of the chamber could thus be controlled by changing the flow rates in theinlet channels, with a complete change of environment within 2 s. The optimum position of the cell array was determinedby simulations, to ensure complete coverage of the intended solution without any concentration gradients over the cellarray. Using a DAPI filter set, the NADH auto fluorescence could be monitored in up to 100 cells simultaneously.Sustained oscillations were successfully induced in individual, isolated cells within specific flow rates andconcentrations of glucose and cyanide. By changing the flow rates without changing the surrounding solution, it wasfound that the cell behavior was dependent on the concentration of chemicals in the medium rather than the flow rates inthe range tested. Furthermore, by packing cells tightly, cell-to-cell interaction and synchronization could be studied.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.