The present invention relates to methods for monitoring in a high through-put fashion a multitude of molecular reaction processes, using a substrate, said substrate comprising a plurality of micro-channels, wherein each micro-channel has inlet and outlet open ends on opposing sides of said substrate, and wherein said micro-channels comprise at least one first reaction component, comprising the steps of: (a) contacting said micro-channels of said solid substrate with a sample, said contacting being via said inlet open ends, wherein said sample comprises an analyte, under conditions that allow said analyte to be specifically retained within said micro-channels by said first reaction component; (b) optionally removing excess of sample via said outlet open ends; (c) contacting the retained analyte with at least one second reaction component, said second reaction component being different from said first reaction component as defined in step (a), under conditions that allow a molecular reaction to take place, said reaction producing a signal; (d) detecting said signal and reading-out reaction results;(e) removing second reaction components via said outlet open ends; (f) repeating steps (c) to (e) at least once, wherein said at least one second reaction component as defined in (c) may be changed in composition; and, final detecting and reading-out of reaction results. The present invention also relates to the uses thereof as well as to microarrays and kits for performing said methods of the invention.