Receding meniscus induced docking of yeast cells inside microfluidic channels at single cell level

We present a simple receding meniscus induced method to capture non-adherent yeast cells onto microwells inside microfluidic channels. Microwells were fabricated by capillary molding onto glass substrate using a UV curable polyurethane acrylate (PUA) solution, leading to well-defined, robust microstructures. A cell suspension of the budding yeast, Saccharomyces cerevisiae, was introduced into microfluidic channels by capillary filling and a receding meniscus was subsequently generated by evaporation. As the meniscus receded, one to five yeast cells were spontaneously captured onto microwells by lateral capillary force created at the thin region of the meniscus. Using this cell-based platform, we observed the response of yeast cells upon stimulation by a mating pheromone (alpha-factor) by monitoring the expression of green fluorescent protein (GFP) with time. It was observed that alpha-factor triggered the expression of GFP at 60 min after stimulation and the fluorescence intensity was sustained for additional 60 min without changes