Abstract: For analyzing a sample containing particles of at least two categories, such as a sample containing blood cells, a particle counter subject to a detection limit is coupled with an analyzer capable of discerning particle number ratios, such as a visual analyzer, and a processor. A first category of particles can be present beyond detection range limits while a second category of particles is present within respective detection range limits. The concentration of the second category of particles is determined by the particle counter. A ratio of counts of the first category to the second category is determined on the analyzer. The concentration of particles in the first category is calculated on the processor based on the ratio and the count or concentration of particles in the second category.

Abstract: An optical apparatus for and method of improving collection efficiency and signal strength of optical instruments used in capillary electrophoresis, such as laser-induced fluorescence detectors are provided. The apparatus and method provides a concave reflector positioned at one side of the capillary flow cell as a first high numerical aperture (N.A.) collector, a lens collector positioned at an opposite side of the flow cell as a second high N.A. collector, and an optical fiber positioned at close proximity of the flow cell for delivery of an excitation light to cause a sample contained in the flow cell to emit emission lights. The reflector has a concave surface for reflecting the emission lights, and the collector has a proximal convex surface for collecting the emission lights, and a distal convex surface for collimating the emission lights. This arrangement achieves a larger solid collection angle from both sides of the flow cell and therefore an increased collection efficiency.