Printing Patterns of Proteins

Microcontact printing of proteins proves to be an excellent means of directly patterning biomolecules on solid substrates. Monolayer quantities of protein equilibrated on the surface of a hydrophobic, elastomeric stamp are immobilized there toward rinses with buffer. These biomolecules can nevertheless transfer with >99% efficiency from the stamp to a substrate after just 1 s of contact. This capability of printing allows the creation of conventional (fluorescence and enzyme-linked) as well as novel assay formats at scales that involve the placement of <1000 molecules in well-defined locations on a surface. One demonstration of the latter type of assay is the use of atomic force microscopy to follow binding of secondary antibodies to their targets immobilized on approx. 1 um2 silicon titer plates, providing a remarkable example of the microcontact printing method.