The invention encompasses microfluidic microarray assemblies (MMA) and subassemblies and methods for their manufacture and use. In one embodiment, first and second channel plates are provided and are sealingly connected to a test chip in consecutive steps. Each plate includes microfluidic channels configured in a predetermined reagent distribution pattern. The test chip comprises a plurality of discrete test positions, each test position being located at the intersection between a first predetermined reagent pattern and a second predetermined reagent pattern, wherein at least one of said patterns is non-linear. The first channel plate allows the distribution of a first reagent on said test chip, wherein said first reagent is immobilized at said test positions. The second channel plate allows the distribution of a second reagent on said test chip, wherein said second reagent comprises a plurality of different test samples.