Abstract: An enhanced detection system can eliminate use of a sheath fluid by selecting which particles that pass through an sensing region to detect parametric characteristics thereof based upon position of each particle while it is in a sensing region relative to one or more predetermined positions, such as an in-focus position relative to one or more light beams directed into the sensing region, to enhance accuracy and robustness of particle parametric characteristics detection.

Abstract: An enhanced detection system can eliminate use of a sheath fluid by selecting which particles that pass through an sensing region to detect parametric characteristics thereof based upon position of each particle while it is in a sensing region relative to one or more predetermined positions, such as an in-focus position relative to one or more light beams directed into the sensing region, to enhance accuracy and robustness of particle parametric characteristics detection.

Abstract: The invention provides a sample detection apparatus, including a polarized radiation source, flow chamber and signal detector, the flow chamber placed to contact polarized radiation from the polarized radiation source, the signal detector is placed to selectively detect radiation propagated from the flow chamber at about 54.7 degrees from the direction of polarization of the contacted polarized radiation. Also provided is a method of detecting fluorescent intensity for a sample in a flow cytometer independent of anisotropic radiation emission. The method includes the steps of: (a) contacting a sample in a flow cytometer with polarized radiation; and (b) detecting radiation emitted by the sample at about 54.7 degrees with respect to the direction of polarization of the polarized radiation at the point of sample contact.

Abstract: The liquid of a flow cytometer itself acts as an optical waveguide, thus transmitting the light to an optical filter/detector combination. This alternative apparatus and method for detecting scattered light in a flow cytometer is provided by a device which views and detects the light trapped within the optical waveguide formed by the flow stream. A fiber optic or other light collecting device is positioned within the flow stream. This provides enormous advantages over the standard light collection technique which uses a microscope objective. The signal-to-noise ratio is greatly increased over that for right-angle-scattered light collected by a microscope objective, and the alignment requirements are simplified.