Multiwell plate device

A multiwell plate device is provided having a frame, a substantially flat substrate and a multiwell structure supported by the substrate. The multiwell structure includes multiple bottomless wells formed therein. The substrate is supported by the frame and may be processed by an automated arrayer or instrument that is used to print or spot arrays in a pattern on a reaction surface of the substrate. Thereafter, the multiwell structure may be engaged with the substrate and the multiwell structure and substrate may be engaged with the frame in an upright orientation. For scanning or other analysis, the multiwell structure and substrate may be disengaged from the frame, inverted 180°, and then reengaged with the frame in the inverted orientation.