Microarray format is the method of choice for high-throughput hybridization of nucleic acids. Lately, microarray strategy has been applied to broad studies of interactions of proteins with other molecules. The diversity of these interactions and variations of the properties of proteins present new challenges to microchip technology. Significant achievements have been reported. In particular, three-dimensional (gel-based) chips can be manufactured with limited resources and offer flexibility, capacity, homogeneous solvent environment and the ability to record processes in real time and in variable conditions.