Observation of live yeast DNA dynamics via multicolor Point Spread Function (PSF) engineering in a microfluidic system

Measuring dynamic genome processes in 3D in real-time in live cells is a significant challenge. Here we develop an integrative system that includes a microfluidic system for live 3D tracking of DNA dynamics during mating-type switching, using multicolor fluorescence microscopy and point-spread-function (PSF) engineering. The microfluidic system enables real-time induction of mating-type switching by medium switching, controlled flow rate and automation. PSF engineering enables encoding of the depth position of the fluorescent point sources at high efficiency and allows 3D imaging. Our system provides the opportunity to explore the process at a single cell level with high throughput. Investigating the mating type switching process which includes a double-strand break, the most toxic DNA damage at the DNA level, may lead to a better understanding of DNA repairing in yeast cells and human cells in the future.