A microfabricated cell curtain is presented that facilitates cellular assays. The cell curtain is defined as a poly(dimethylsiloxane) (PDMS) wall that extends from the ceiling of a cell culture microchamber to within microns of the chamber floor. Curtain use is demonstrated by observing monolayer human epidermal keratinocyte (HEK) colonies for 48 h longer than possible with non-curtained microfluidic chambers. The curtains were further characterized by integrating them into a 96 chamber high throughput microfluidic cell culture device. As proof of concept, this device was used to assay a range of ethanol dilutions spanning 0-22% in cell culture medium. Cells exposed to 12% ethanol or less for 30 min would recover to 85% viability at 24 h, while cells exposed to higher concentrations had viabilities below 10%. The data also showed that cells exposed to 6% ethanol or less grew in population size, 8% ethanol exposure stunted growth, and higher concentrations led to population loss. Curtain use permitted high initial cell seeding densities and increased the amount of time cells can be cultured compared to multi-well plates.