Patent ID: 7709271

Claim:
A device for determining a concentration of a biological active substance in a sample from an optical signal emitted during an enzyme-linked immunosorbent assay (ELISA), performed on the sample using ELISA related fluids which include an enzyme-labeled immunoreactant and an enzyme substrate, the device comprising: a microchip having a plate-like configuration and extending substantially in one plane, the microchip further having at least one light permeable portion; a tubing inside the microchip and extending in the plane of the microchip, a portion of the tubing forming a reaction cell from which the optical signal is emitted during the assay, the reaction cell encompassing one of either a plurality of curves of the tubing portion or a portion of the tubing which is wider in the reaction cell than in other portions of the microchip, the reaction cell located adjacent to the light permeable portion to transmit the optical signal substantially perpendicularly to the plane of the microchip; a solid support within the tubing in the reaction cell for binding an immunosorbent, the solid support and the tubing within the reaction cell forming an active surface continuously along the entire reaction cell for reaction of the substance with the immunosorbent and ELISA related fluids to produce the optical signal over substantially the entire length of the tubing in the reaction cell during the assay; and a detector arranged substantially perpendicular to the reaction cell and adjacent to the light permeable portion for detecting the optical signal emitted over substantially the entire length of the tubing in the reaction cell wherein the reaction cell encompasses the plurality of curves in the tubing; and every other curve of the tubing in the reaction cell is substantially a 180° curve to the right and the remaining intervening curves are substantially 180° curves to the left wherein the distance between each curve of the tubing is increasing in a direction towards a centre position of the reaction cell and is decreasing in a direction away from the centre position of the reaction cell.