Ethanol Precipitation of Aptamers after PAGE Purification. Aptamers were desalted by ethanol precipitation; the samples were incubated with 3 M sodium acetate and 100% ethanol over night before being centrifuged for 20 minutes. The supernatant was removed, and the pellet washed with 1 mL of ethanol and centrifuged again; this was repeated three times for each sample. The samples were then left to air dry before being re-suspended in autoclaved water. Sorting MinE07Lib to extract the top binding MinE07 modified aptamers. All of the MinE07Library (1 µM, 0.0029 g) was added to an Eppendorf tube. Binding buffer (100 µL) was added and the tube was incubated at room temperature for 15 minutes. This was centrifuged at 300rpm for 1 minute; the binding buffer was removed and the microspheres were then washed with binding buffer (2 x 100 µL). EGFR-Fc (0.03357 mg/mL, 100 µL) was then added to the tube and this was incubated at room temperature for 60 minutes. This was spun down at 300 rpm for 1 minute, the EGFR-Fc was removed, and the microspheres were then washed with wash buffer (2 x 100 µL). Protein A-FITC (0.03357 mg/mL, 100 µL) was then added to the tube and this was incubated at room temperature for 60 minutes. This was spun down at 300 rpm for 1 minute, the Protein A-FITC was removed, and the microspheres were then washed with wash buffer (2 x 100 µL). Sheath fluid (4 mL) was added, and the microspheres sonicated. The sample was then added to a FACS sized falcon tube. Standard calibration was performed. The MinE07Lib-EGFR-Fc-Protein-A-FITC microspheres sample was twoway sorted three times, changing the gates each time to match the photobleaching and to select less each time. The FACS was calibrated using the 96 well plate set up program along with the accudrop beads. The top microspheres selected from the first three rounds of sorting the MinE07Lib-EGFR-Fc-Protein-A-FITC microsphere were then sorted across two 96 well plates with 100 µL of RO water. The 488 nm laser was used with filter 513/17 nm. All data was collected and analysed using the BD FACS Sortware sorter software program.