Abstract: Cell counters and methods of their use are disclosed herein. The cell counters include a sample mounting system that includes a base, which includes a mounted lower sample surface and a cover having a mounted upper sample surface; a bright-field light source incorporated in the cover; an objective lens mounted below the sample mounting system; optionally, a fluorescence excitation source in optical communication with the sample mounting system; and an imaging system in optical communication with the bright-field light source and the objective lens. The mounted sample surfaces are configured for repeated use, such that disposable sample cartridges are not needed.

Abstract: Cell counters and methods of their use are disclosed herein. The cell counters comprise a sample mounting system that includes a base comprising a mounted lower sample surface and a cover comprising a mounted upper sample surface; a bright-field light source incorporated in the cover; an objective lens mounted below the sample mounting system; optionally, a fluorescence excitation source in optical communication with the sample mounting system; and an imaging system in optical communication with the bright-field light source and the objective lens. The mounted sample surfaces are configured for repeated use, such that disposable sample cartridges are not needed.

Abstract: Cell counters and methods of their use are disclosed herein. The cell counters comprise a sample mounting system that includes a base comprising a mounted lower sample surface and a cover comprising a mounted upper sample surface; a bright-field light source incorporated in the cover; an objective lens mounted below the sample mounting system; optionally, a fluorescence excitation source in optical communication with the sample mounting system; and an imaging system in optical communication with the bright-field light source and the objective lens. The mounted sample surfaces are configured for repeated use, such that disposable sample cartridges are not needed.

Abstract: Cell counters and methods of their use are disclosed herein. The cell counters comprise a sample mounting system that includes a base comprising a mounted lower sample surface and a cover comprising a mounted upper sample surface; a bright-field light source incorporated in the cover; an objective lens mounted below the sample mounting system; optionally, a fluorescence excitation source in optical communication with the sample mounting system; and an imaging system in optical communication with the bright-field light source and the objective lens. The mounted sample surfaces are configured for repeated use, such that disposable sample cartridges are not needed.

Abstract: An apparatus and method for measuring fluorescence of a sample is described. An apparatus includes three or more fluorescence channels passing through a sample site. The three or more fluorescence channels allow for exposing a sample at the sample site to light from three or more light sources, which results in fluorescence measurements based on emissions from the sample in response to the three or more light sources.

Abstract: An improved apparatus and method for making optical measurements of a sample is described. In one embodiment, the apparatus is a microvolume sampling mechanism comprised of two opposing optical measurement surfaces. A sample is held by surface tension between the two opposing optical measurement surfaces. Light is transmitted through the sample and received by optical fibers, which measure the absorbance of the sample. This absorbance can be used to determine the concentration of the sample.

Abstract: An improved apparatus and method for making optical measurements of a sample is described. In one embodiment, the apparatus is a microvolume sampling mechanism comprised of two opposing optical measurement surfaces. A sample is held by surface tension between the two opposing optical measurement surfaces. Light is transmitted through the sample and received by optical fibers, which measure the absorbance of the sample. This absorbance can be used to determine the concentration of the sample.