Every 24 hours, cells on 2-D controls (Matrigel-coated TCPS) and in 100, 300, and 500 μm/side microwells were pulsed with bromodeoxiuridine (BrdU) for 20 minutes. After BrdU treatment, the cells were harvested and the percentage of BrdU-positive cells was determined using flow cytometry. Microwell-cultured cells contained a lower percentage of BrdU-positive cells than 2-D controls, indicating a reduction in proliferative capacity (* indicates P<0.05 compared to same-day 2-D control).