Abstract: An apparatus for time-gated fluorescence or luminescence detection includes gating means (206) arranged to alternately permit light from an excitation source (242) to be directed to a sample (235) along a first communication path (231, 232), and then permit light emitted from the sample to be directed to a detector (246) along a second communication path (237, 238) while blocking the first communication path (231, 232): The gating means (206) may comprise a single chopper wheel or apertured disc, or a rotating or oscillating arm, and may further comprise one or more reflective facets (207). The gating means (206) may be driven via a magnetic rotor, with a ferrite bead placed to offset rotor magnets with respect to drive coils, when at rest, so as to assist with self starting.

Abstract: An apparatus for time-gated fluorescence or luminescence detection includes gating means (206) arranged to alternately permit light from an excitation source (242) to be directed to a sample (235) along a first communication path (231, 232), and then permit light emitted from the sample to be directed to a detector (246) along a second communication path (237, 238) while blocking the first communication path (231, 232): The gating means (206) may comprise a single chopper wheel or apertured disc, or a rotating or oscillating arm, and may further comprise one or more reflective facets (207). The gating means (206) may be driven via a magnetic rotor, with a ferrite bead placed to offset rotor magnets with respect to drive coils, when at rest, so as to assist with self starting.

Abstract: A fluorescence detection system comprises a light source (22), dichroic mirror (32), excitation port (16), emission port (14), and a detector. The light source (22) is, for example, a pulsed ultraviolet LED, with a light emission that decays sufficiently rapidly to permit gated detection of fluorescence from a fluorescently-labelled species, at a time when it is distinguishable from autofluorescence. The detector is, for example, an electron multiplying CCD, with high gain on-chip amplification. A circuit (26) may be used to control a repeating cycle of (i) generation of a 20-200 microsecond UV. pulse; (ii) a gate delay of 1-5 microseconds; and (iii) a 10-800 microsecond detection period. This allows time-resolved-fluorescence-microscopy with real time or near real time operation.

Abstract: An apparatus (10) for detecting a particle (12) labelled with a fluorescent marker is disclosed. The apparatus (10) has a flow cell (16) being adapted to contain a fluid (14) in which the particle (12) is suspended. A light source (28) is operatively coupled to the flow cell (16) and arranged for emitting a stimulating light (28) which is effective in optically exciting the fluorescent marker (12) for emitting a fluorescent light (30). The apparatus (10) also includes a spatial filter (50) across an optical path between the particle (12) and a time gated detector (32) operatively coupled to the flow cell (16) for detecting the fluorescent light (30).

Abstract: A fluorescence detection system comprises a light source (22), dichroic mirror (32), excitation port (16), emission port (14), and a detector. The light source (22) is, for example, a pulsed ultraviolet LED, with a light emission that decays sufficiently rapidly to permit gated detection of fluorescence from a fluorescently-labelled species, at a time when it is distinguishable from autofluorescence. The detector is, for example, an electron multiplying CCD, with high gain on-chip amplification. A circuit (26) may be used to control a repeating cycle of (i) generation of a 20-200 microsecond UV. pulse; (ii) a gate delay of 1-5 microseconds; and (iii) a 10-800 microsecond detection period. This allows time-resolved-fluorescence-microscopy with real time or near real time operation.