Protein micropatterns: A direct printing protocol using deep UVs.

The described protocol is a simple method to make protein micropatterns with a micron size resolution. It can be applied to control cell shape and adhesive geometry, and also for any other assay requiring protein patterning. It is based on the use of a photomask with microfeatures to locally irradiate with deep UV light (below 200 nm) an antifouling substrate, making it locally adsorbing for proteins. The entire process can be subdivided into three main parts. The first part describes the design of a photomask. The second part describes the passivation (antifouling treatment) of the substrate, its irradiation, and the binding of proteins. The entire process can be completed in a couple of hours. It requires no expensive equipment and can be performed in any biology lab. The last part describes cell deposition on the micropatterned substrate. We also provide a discussion with pitfalls and alternative techniques adapted to various substrates, including silicone elastomers.