Abstract: A flow path comprising a reaction cavity in which there is a solid phase to which an affinity reactant I1 has been immobilized by the use of an immobilizing pair of reactive structures that comprises a) a plurality of functional equal structures RSsp on the solid phase, and b) a structure RSari on affinity reactant I1, where RSsp and RSari are mutually reactive with each other to the formation of a link structure that immobilizes affinity reactant I1 to the solid phase. The characteristic feature is that the solid phase comprises a plurality of structures that derive from RSsp but do not immobilize affinity reactant I1 to the solid phase.

Abstract: A detector arrangement, which comprises a rotatable microfluidic disc and a spectrophotometric detector unit. The arrangement is characterized in that the detector unit is based on surface plasmon resonance (SPR) and is capable of measuring an analyte within the detection microcavities, each of which is part of a microchannel structure. A microfluidic disc having an axis of symmetry and comprising microchannel structures, each of which has an upstream functional part that is at a shorter radial position than a downstream functional part. The disc is characterized in that there are detection microcavities (DMCs) in at least a part of said microchannel structures, and that each of said DMCs has an SPR surface on an inner wall and a detection detection window extending from the SPR surface to the surface of the disc.

Abstract: Method for measuring the signal from a label in a labeled measuring reagent that has been specifically adsorbed to its affinity counterpart in a zone of a porous nanolitre (nl) bed that is present in a microchannel structure of a microfluidic device. The measuring is part of an assay for determining an analyte of a sample by performing one, two or more heterogeneous specific affinity reactions which comprises that said labeled measuring reagent becomes affinity bound to said zone.

Abstract: A detector arrangement, which comprises a rotatable microfluidic disc and a spectrophotometric detector unit. The arrangement is characterized in that the detector unit is based on surface plasmon resonanc (SPR) and is capable of measuring an analyte within the detection microcavities, each of which is part of a microchannel structure. A microfluidic disc having an axis of symmetry and comprising microchannel structures, each of which has an upstream functional part that is at a shorter radial position than a downstream functional part. The disc is characterized in that there are detection microcavities (DMCs) in at least a part of said microchannel structures, and that each of said DMCs has an SPR surface on an inner wall and a detection detection window extending from the SPR surface to the surface of the disc.