Fabrication of a Microfluidic Cell Culture Device Using Photolithographic and Soft Lithographic Techniques

Photolithography and soft lithography are two common methods for fabrication of microfluidic cell culture devices. Well-defined microstructures are created by exposing a photoresist to UV-light under a photolithographic mask in which the intended patterns are transparent. The subsequent cross-linking of UV-exposed photoresist generates a reusable master that serves as a template for an elastomer, commonly polydimethylsiloxane (PDMS), that reciprocally recaptures the structures of the master in an optically clear and oxygen-permeable rubber-like material. Connections to the cell culture-containing channels of the device for perfusion of culture medium can be established by inserting tubing through the elastomer. In this protocol, the basic steps for making a standard microfluidic device for cell-based assays from photolithography and soft lithography techniques are outlined.