ASSAYS BASED ON LIQUID FLOW OVER ARRAYS

摘要

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. A blister pack (11) acts as a reversible pump (12) in producing accurate forward and backward flows with the net flow advance. Cascaded bubble traps (8, 9) on the cassette render the system tolerant of minor pumping error during cassette priming.