Systems and methods for analyzing blood samples, and more specifically for performing a white blood cell (WBC) differential analysis. The systems and methods screen WBCs by means of fluorescence staining and a fluorescence triggering strategy. As such, interference from unlyzed red blood cells (RBCs) and fragments of lysed RBCs is substantially eliminated. The systems and methods also enable development of relatively milder WBC reagent(s), suitable for assays of samples containing fragile WBCs. In one embodiment, the systems and methods include: (a) staining a blood sample with an exclusive cell membrane permeable fluorescent dye, which corresponds in emission spectrum to an excitation source of a hematology instrument; (b) using a fluorescence trigger to screen the blood sample for WBCs; and (c) using measurements of (1) axial light loss, (2) intermediate angle scatter, (3) 90 polarized side scatter, (4) 90 depolarized side scatter, and (5) fluorescence emission to perform a differentiation analysis.

A detection of the Gram type of a bacterial strain includes: illumination, in the wavelength range 415 nm-440 nm, of at least one bacterium of said strain having a natural electromagnetic response in said range; acquisition, in the range 415 nm-440 nm, of a light intensity reflected by, or transmitted through, said illuminated bacterium; and determination of the Gram type of the bacterial strain as a function of the light intensity acquired in the range 415 nm-440 nm.

A bacteria detection device moves a stage on which a detection chip is placed with a membrane filter fixed thereon by a first driving mechanism and a second driving mechanism in front-rear direction and in left-right direction so that an image of an upper surface of the membrane filter to which excitation light from a light emitter aligned with a imaging range by an imaging unit is taken. If bacteria to which a fluorescent label has been bound is captured on the upper surface of the membrane filter, the imaging unit can take an image of the bacteria as luminous points. A controller counts the luminous points in the image taken by the imaging unit so that the bacteria captured on the upper surface of the membrane filter can be detected.

A spectroscopic measurement device emits light to a measurement target and measures the measurement light output from the measurement target in accordance with the light emission. A spectroscopic measurement device includes: a first housing having a light shielding property and configured to house a light source that emits light and having a first opening through which the light emitted from the light source passes; a second housing having a light shielding property and having a second opening through which the measurement light passes and configured to house a spectrometer that receives the measurement light that has passed through the second opening; and an attachment configured to detachably hold the first housing and the second housing.

A system and method for determining impurities in a beverage grade gas such as CO.sub.2 or N.sub.2 relies on a coupling of FTIR analysis and UV fluorescence detection. Conversion of reduced sulphur present in some impurities to SO.sub.2 can be conducted using a furnace. In some cases, CO.sub.2 % also is determined.

An optical detection system for a capillary electrophoresis instrument is disclosed. The system includes an ultraviolet (UV) source and an absorption measurement optical path. In an embodiment, the optical path comprises a first plurality of optical elements arranged to obtain a plurality of respective UV beamlets from a UV beam emitted by the UV source and to direct the respective UV beamlets transversely through respective capillaries of a plurality of capillaries and to an absorption detector positioned to detect respective signals for use in obtaining respective UV absorption measurements corresponding to the respective capillaries.

A process for measuring a size distribution of a plurality of nucleic acid molecules, the process comprising: labeling the nucleic acid molecules with a fluorescent dye comprising a plurality of fluorescent dye molecules to form labeled nucleic acid molecules, such that a number of fluorescent dyes molecules attached to each nucleic acid molecule is reliably proportional to the number of base pairs in the nucleic acid molecule, the fluorescent dye molecules having a first florescence spectrum; producing, by the labeled nucleic acid molecules, the first florescence spectrum in response to irradiating the labeled nucleic acid molecules at the first wavelength; and detecting the first florescence spectrum to measure the size distribution of the plurality of nucleic acid molecules.

Systems and methods for optimizing detection of light-emissive components of a multi-fluorescence spectra. The method comprises obtaining a multi-fluorescence based spectra of a plurality of light-emissive components and determining a model of ensemble multi-fluorescence of said light-emissive components that are stochastically distributed.

Techniques are disclosed relating to fluorescence-based flow cytometry. A flow cytometer may include a partially-reflective surface configured to reflect a first portion of fluorescent emissions from a sample to a first optical sensor and direct a second, greater portion of fluorescent emissions from the sample to a second optical sensor and a controller configured to determine a value representing the intensity of the fluorescent emissions based on a first measurement taken by the first optical sensor, a second measurement taken by the second optical sensor, or both. A flow cytometer may include a baseplate with a first side and a second, opposing side with a flow cell, a laser, and a reflective surface disposed above the first side and an optical sensor and isolating material disposed below the second side. The reflective surface receives fluorescent emissions and reflects at least a portion through the baseplate to the optical sensor. A flow cytometer may include a flow cell, a laser, a first optical sensor positioned to measure scattered laser light, a second optical sensor positioned to measure fluorescent emissions, and a controller configured to adjust the measurements taken by the second optical sensor based on a comparison of measurements taken by the first optical sensor with expected measurements based on a known beam profile of the laser beam.

A measuring device for measuring a measurand of a medium includes a measuring cell, a measuring cell receptacle for holding the measuring cell, and a measuring apparatus for measuring the measurand, wherein the measuring cell includes a measurement chamber containing the medium and a reference chamber separate from the measurement chamber and containing a reference medium. The measurement chamber and the reference chamber are arranged relative to one another such that the measuring cell can be inserted into the measuring cell receptacle in a measuring position, in which measurements of the measurand of the medium can be performed by means of the measuring apparatus, and can be inserted into the measuring cell receptacle in a reference position, in which reference measurements of a reference variable of the reference medium in the reference chamber can be performed by means of the measuring apparatus.