We developed a simple system that regulates CO2 and O2 levels within a microfluidic chip. This system enables long-term cell culture under hypoxic conditions without the need of a CO2 incubator or a multi-gas incubator. Hypoxic conditions were generated using a miniature water jacket containing dissolved ascorbate as an oxygen scavenger. Formulations of the water jacket were determined that enables both 5% pCO2 and desired pO2 levels ranging from 5 to 15%. We also cultured PC-12 cells and primary neuronal cells from chick embryos under hypoxia and observed hypoxia-induced cell death and inhibition of neurite outgrowth.