Figure A4. Microfluidics gradient chamber set-up.

Microfluidics devices are made from a PDMS component with the chamber features and a glass slide. (A) After these two pieces are plasma cleaned, they fuse by creating covalent Si-O-Si bonds. (B) A detailed schematic of the microfluidic device shows how a gradient is created inside of the chamber and (C) shows the intensity of the fluorescent dye across the width of the chamber.