Analyses of cellular responses to fast oxygen dynamics are challenging and require ad hoc technological solutions, especially when decoupling from liquid media composition is required. In this work, we present a microfluidic device specifically designed for culture analyses with high resolution and magnification objectives, providing full optical access to the cell culture chamber. This feature allows fluorescence-based assays, photoactivated surface chemistry, and live cell imaging under tightly controlled pO<sub>2</sub> environments. The device has a simple design, accommodates three independent cell cultures, and can be employed by users with basic cell culture training in studies requiring fast oxygen dynamics, defined media composition...