PDMS slabs were removed using a razor blade. Three-millimeter biopsy punches (Tru-punch, Skylar Instruments) were compressed using pliers to create a slight oval shape. Two holes were punched into the PDMS to form each of the two compartments within a well (4 punches per well, 2 on each side to allow air escape during filling). The PDMS slabs were then washed with isopropanol followed by water and allowed to fully dry. The PDMS was bonded to a 74 mm × 108 mm × 0.17 mm thick glass plate (0CON-160, Logitech, Ltd., Glasgow, UK) using oxygen plasma (March PX-250, 100 W, 60 s, 60% O2), bonded, and placed on a hotplate at 95 °C under light weight for 30 minutes. The PDMS/glass substrate was next bonded to the bottom of a μClear 96 well plate (Greiner Bio-One), which was used as a structure on which to attach the microfluidic PDMS slab. Prior to bonding, the well bottoms of the microplate were punched out using a 10 μl pipette tip (the tip head was pressed into the well bottom to punch out
