Abstract: Cassette (50) performs assays, e.g. multiplexed protein biomarker assays. Wide, bubble-free, slow flows are produced from liquids stored on cassette (50), flowing over wide array (20) of ligand receptors on a capture surface. Flows of Reynolds Number less than about 1, preferably 1×10?1 to 5×10?3, are heated in region (34) preceding and including bubble removal system (128). Analyte is introduced through compressed septum (32). External actuations of displacement pumps (30, 37) and valves (137 A, B, and C) produce flows in response to flow-front optical sensors (150, 152). Elastic sheet provides pump and valve diaphragms and resilient expansion of mixing volume (131). Break-away cover portions are pistons. Heating is by conduction through cassette from external contact heater. Planar cassette body, when tilted from horizontal, enables upward flow from pumped storage (134, 135) to reaction (133) to waste (139), with buoyancy bubble removal before reaction.

Abstract: Flow-through assay reaction chamber (6) of cassette has back and forth liquid mixing in narrow gap (G) over array of capture agent (S), with net flow advance to waste confinement (19), produced by reversible pumps (3 or 12), operable with rolling diaphragm action with at least limited elastic recovery that advance sample or buffer liquids through conditioning paths (4A, 8, 8?, 9, 14, 15, 15?) before reaching the reaction chamber (6). A single pump produces accurate flow control, liquid conditioning, e.g., liquefying dry reagent from internal surfaces of flow-dividing material (14a, 15A, 15A?, e.g. open cell foam or frit), heating (4A), and air bubble removal (8, 8?, 9), as well as replenishment of reagent while accomplishing mixing within the flow-through reaction chamber (6). Lower viscosity buffer liquid is arranged to propel higher viscosity reagent, the flow-dividing storage material preserving reagent concentration.

Abstract: An immobilizing device for biological material comprises a rigid support (12) carrying a substrate layer (20, 20?) of polymer having biological immobilizing properties, e.g. for amino and nucleic acids. Substantially solid ultra-thin substrate layers (20?) having a thickness less than about 5 micron, preferably between about 0.1 and 0.5 micron, and microporous, ultra-thin substrate layers (20?) having a thickness less than about 5 micron, preferably less than 3 micron, 2 or 1 micron are shown, which may be segmented by isolating moats M. The substrate layer is on a microscope slide (302), round disc (122), bio-cassette, at the bottom of a well of a multiwell plate, and as a coating inside a tube. Fluorescence or luminescence intensity and geometric calibration spots (420) are shown. Reading is enhanced by the intensity calibration spots (420) to enable normalization of readings under uneven illumination conditions, as when reading by dark field, side illumination mode.