Abstract: In apparatus for the production and detection of fluorescence at a sample surface, the height of the apparatus above the sample surface is reduced, and loss of the emitted fluorescence due to reflection loss and light scattering is minimized. The apparatus comprises a three-dimensionally curved light reflecting surface (40) that directs light from a light source (32) transversely to its original path and focuses the light on to an illumination zone (30) at or below the sample surface. The reflecting surface (40) also collects, directs and at least partially collimates emitted fluorescence transversely to its original path and towards a detector (46).

Abstract: A reagent for use in detecting an analyte comprises a fluorescent energy donor and an energy acceptor, wherein the energy acceptor is of the general formula: and wherein the distance between the energy donor and the energy acceptor of the reagent is capable of modulation by a suitable analyte to be detected.

Abstract: A first light source emits a light signal along a measurement optical path that includes a sample and a second light source emits a light signal along a dummy measurement optical path. A measurement circuit receives the light signals and provides outputs separated in time which are indicative of the phase of the respective light signals. A phase shift is induced in light in the measurement optical path by the sample. A reference circuit receives a signal indicative of the phase of the light signals emitted by the first and second light sources. Circuitry compares the phases of light output from the two circuits to provide output indicative of a first measured phase difference during operation of the first light source. Correction is applied to this measurement by taking a similar phase difference measurement during operation of the second light source and comparing the two phase differences.

Abstract: In apparatus for the production and detection of fluorescence at a sample surface, the height of the apparatus above the sample surface is reduced, and loss of the emitted fluorescence due to reflection loss and light scattering is minimized. The apparatus comprises a three-dimensionally curved light reflecting surface (40) that directs light from a light source (32) transversely to its original path and focuses the light on to an illumination zone (30) at or below the sample surface. The reflecting surface (40) also collects, directs and at least partially collimates emitted fluorescence transversely to its original path and towards a detector (46).

Abstract: A reagent for use in detecting an analyte comprises a fluorescent energy donor and an energy acceptor, wherein the energy acceptor is of the general formula: and wherein the distance between the energy donor and the energy acceptor of the reagent is capable of modulation by a suitable analyte to be detected.

Abstract: A first light source emits a light signal along a measurement optical path that includes a sample and a second light source emits a light signal along a dummy measurement optical path. A measurement circuit receives the light signals and provides outputs separated in time which are indicative of the phase of the respective light signals. A phase shift is induced in light in the measurement optical path by the sample. A reference circuit receives a signal indicative of the phase of the light signals emitted by the first and second light sources. Circuitry compares the phases of light output from the two circuits to provide output indicative of a first measured phase difference during operation of the first light source. Correction is applied to this measurement by taking a similar phase difference measurement during operation of the second light source and comparing the two phase differences.

Abstract: In apparatus for the production and detection of fluorescence at a sample surface, the height of the apparatus above the sample surface is reduced, and loss of the emitted fluorescence due to reflection loss and light scattering is minimized. The apparatus comprises a three-dimensionally curved light reflecting surface (40) that directs light from a light source (32) transversely to its original path and focuses the light on to an illumination zone (30) at or below the sample surface. The reflecting surface (40) also collects, directs and at least partially collimates emitted fluorescence transversely to its original path and towards a detector (46).

Abstract: In apparatus for the production and detection of fluorescence at a sample surface, the height of the apparatus above the sample surface is reduced, and loss of the emitted fluorescence due to reflection loss and light scattering is minimized. The apparatus comprises a three-dimensionally curved light reflecting surface (40) that directs light from a light source (32) transversely to its original path and focuses the light on to an illumination zone (30) at or below the sample surface. The reflecting surface (40) also collects, directs and at least partially collimates emitted fluorescence transversely to its original path and towards a detector (46).

Abstract: A first light source emits a light signal along a measurement optical path that includes a sample and a second light source emits a light signal along a dummy measurement optical path. A measurement circuit receives the light signals and provides outputs separated in time which are indicative of the phase of the respective light signals. A phase shift is induced in light in the measurement optical path by the sample. A reference circuit receives a signal indicative of the phase of the light signals emitted by the first and second light sources. Circuitry compares the phases of light output from the two circuits to provide output indicative of a first measured phase difference during operation of the first light source. Correction is applied to this measurement by taking a similar phase difference measurement during operation of the second light source and comparing the two phase differences.

Abstract: In apparatus for the production and detection of fluorescence at a sample surface, the height of the apparatus above the sample surface is reduced, and loss of the emitted fluorescence due to reflection loss and light scattering is minimized. The apparatus comprises a three-dimensionally curved light reflecting surface (40) that directs light from a light source (32) transversely to its original path and focuses the light on to an illumination zone (30) at or below the sample surface. The reflecting surface (40) also collects, directs and at least partially collimates emitted fluorescence transversely to its original path and towards a detector (46).

Abstract: A first light source emits a light signal along a measurement optical path that includes a sample and a second light source emits a light signal along a dummy measurement optical path. A measurement circuit receives the light signals and provides outputs separated in time which are indicative of the phase of the respective light signals. A phase shift is induced in light in the measurement optical path by the sample. A reference circuit receives a signal indicative of the phase of the light signals emitted by the first and second light sources. Circuitry compares the phases of light output from the two circuits to provide output indicative of a first measured phase difference during operation of the first light source. Correction is applied to this measurement by taking a similar phase difference measurement during operation of the second light source and comparing the two phase differences.

Abstract: A sensor for sensing analyte concentration comprises at least two different variants of an appropriate competitive binding assay, the sensor being capable of sensing accurately a required range of analyte concentrations by means of the variants of the assay each being capable of sensing accurately a part only of the required range of analyte concentrations and the variants of the assay being chosen to sense overlapping or adjoining ranges of concentration covering the whole of the required range.

Abstract: The invention relates to a sensor for the in vivo measurement of an analyte, comprising a plurality of particles of suitable size such that when implanted in the body of a mammal the particles can be ingested by macrophages and transported away from the site of implantation, each particle containing the components of an assay having a readout which is an optical signal detectable transdermally by external optical means, and either each particles being contained within a biodegradable material preventing ingestion by the macrophages, or each particle being non-biodegradable. The invention relates to a process for the detection of an analyte using such a sensor, comprising implantation of the sensor into the skin of a mammal, transdermal detection of analyte using external optical means, degradation of the biodegradable material, ingestion of the particles by macrophages, and removal of the particles from the site of implantation by macrophages.

Abstract: An injection apparatus is described for making an injection at a predetermined depth in skin, including: a skin positioning member for positioning on a patch of skin within an area of skin such that at least a part of the patch of skin may be held elevated above or depressed below the area of skin, an injection needle, and a guidance mechanism for guiding the injection needle to slide beneath the skin positioning member to an injection position in which the distal end of the needle lies at a predetermined distance below the skin positioning member. An injection apparatus is also described including a detachable marker unit and a securing element for securing the marker unit at an injection site prior to the making of an injection to mark the position of the injection site.

Abstract: An assay implantation apparatus is provided comprising a sensor for use for the in vivo measurement of an analyte and means for implanting said sensor within an upper layer of the skin from which it is naturally ejected over time by growth of the skin and progressive replacement of the outer layer of the skin. The sensor may comprise microparticles containing a chemical assay system into which an analyte may diffuse from intercellular fluid and which assay system can be interrogated remotely by a light signal and a fluorescence sensor.