title: A single-step photolithographic interface for cell-free gene expression and active biochips.
abstract: We have developed a biochip platform technology suitable for controlled cell-free gene expression at the micrometer scale. A new hybrid molecule, "Daisy", was designed and synthesized to form in a single step a biocompatible lithographic interface on silicon dioxide. A protocol is described for the immobilization of linear DNA molecules thousands of base pairs long on Daisy-coated surfaces with submicrometer spatial resolution and up to high densities. On-chip protein synthesis can be obtained with a dynamic range of up to four orders of magnitude and minimal nonspecific activity. En route to on-chip artificial gene circuits, a simple two-stage gene cascade was built, in which the protein synthesized at the first location diffuses to regulate the synthesis of another protein at a second location. We demonstrate the capture of proteins from crude extract onto micrometer-scale designated traps, an important step for the formation of miniaturized self-assembled protein chips. Our biochip platform can be combined with elastomeric microfluidic devices, thereby opening possibilities for isolated and confined reaction chambers and artificial cells in which the transport of products and reagents is done by diffusion and flow. The Daisy molecule and described approach enables groups not proficient in surface chemistry to construct active biochips based on cell-free gene expression.
authors.affiliation: Departments of Materials and Interfaces, The Weizmann Institute of Science, PO Box 26, Rehovot 76100, Israel.
authors.forename: Amnon
authors.initials: A
authors.lastname: Buxboim
authors.forename: Maya
authors.initials: M
authors.lastname: Bar-Dagan
authors.forename: Veronica
authors.initials: V
authors.lastname: Frydman
authors.forename: David
authors.initials: D
authors.lastname: Zbaida
authors.forename: Margherita
authors.initials: M
authors.lastname: Morpurgo
authors.forename: Roy
authors.initials: R
authors.lastname: Bar-Ziv
mesh_terms: D002474:Cell-Free System; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D020869:Gene Expression Profiling / Q000379:methods*; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010316:Particle Size; D010781:Photography; D040081:Protein Array Analysis / Q000379:methods*; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible