Analyte collection and testing systems and methods, and more particularly to disposable oral fluid collection and testing systems and methods. Described herein are methods and apparatuses to achieve significant improvements in the detection of fluorescence signals in the reader.

Fluorescence imaging system designs are described that provide larger fields-of-view, increased spatial resolution, improved modulation transfer and image quality, higher spatial sampling frequency, faster transitions between image capture when repositioning the sample plane to capture a series of images (e.g., of different fields-of-view), and improved imaging system duty cycle, and thus enable higher throughput image acquisition and analysis for genomics and other imaging applications.

Systems and methods for sensing vibrational absorption induced photothermal effect via a visible light source. A Mid-infrared photothermal probe (MI-PTP, or MIP) approach achieves 10 mM detection sensitivity and sub-micron lateral spatial resolution. Such performance exceeds the diffraction limit of infrared microscopy and allows label-free three-dimensional chemical imaging of live cells and organisms. Distributions of endogenous lipid and exogenous drug inside single cells can be visualized. MIP imaging technology may enable applications from monitoring metabolic activities to high-resolution mapping of drug molecules in living systems, which are beyond the reach of current infrared microscopy.

A system, an apparatus, and a method are provided for a modular flow cytometer with a compact size. In one embodiment, the modular flow cytometry system includes the following: a laser system for emitting laser beams; a flow cell assembly positioned to receive the laser beams at an interrogation region of a fluidics stream where fluoresced cells scatter the laser beams into fluorescent light; a fiber assembly positioned to collect the fluorescent light; and a grating system including a dispersive element and a receiver assembly, wherein the dispersive element is positioned to receive the fluorescent light from the fiber assembly and to direct spectrally dispersed light toward the receiver assembly.

Method and gas analyzer for measuring the concentration of a gas component in a sample gas, wherein to measure the concentration of a gas component in a sample gas, a laser diode is actuated by a current and light generated by the laser diode is guided through the sample gas to a detector, the current is simultaneously varied within periodically successive sampling intervals for the wavelength-dependent sampling of an absorption line of interest of the gas component, and the current can be additionally modulated sinusoidally based on wavelength modulation spectroscopy with a low frequency and small amplitude, such that a measuring signal generated by the detector is evaluated to form a measurement result, where to improve the measuring signal-noise ratio and achieve a much lower detection limit with the same measuring distance, the current is modulated with a high (RF) frequency in the GHz range so that no wavelength modulation occurs, and an RF modulation amplitude is selected at the maximum level using the linear control range of the laser diode where, before evaluation, the measuring signal is demodulated at the radio frequency.

A device and method of use are provided for measuring the concentration of fatty acid methyl ester (FAME) in jet fuel to a limit of detection of 1 ppm. The device measures concentration of FAME in jet fuel via Fourier transform infrared spectroscopy (FTIR) with a spectral resolution of 1 cm.sup.−1. The device can use an infrared light emitting diode (IR LED) and mercury cadmium telluride (MCT) detector in which the spectral output of the IR LED and the spectral response of the MCT detector is centered on the spectral absorbance of an ester bond, a defining spectral characteristic of FAME. Other IR LEDs with differing spectral outputs can be used to measure the presence and/or concentration of different analytes in different fluids.

Analyte content in a cell free portion of a body fluid, such as blood, is optically determined without centrifugation or other preliminary steps for separating the cell free portion from the body fluid. A channel is configured for containing a flowing sample of the body fluid along an optical boundary. The channel is configured so that a cell free layer of the fluid naturally forms along the boundary of the channel which coincides with the optical boundary. A light source is directed onto the optical boundary at an angle selected to generate total reflection from the boundary and to generate an evanescent field across the boundary in the cell free layer of fluid. A light detector is configured to detect absorption of the light in the evanescent field. The light source and light detector are matched to the wavelength range of an absorption peak of the analyte being detected.

The preparation holding device of a microtome can be pivoted via a ball head. To pivot the preparation holding device, actuators are assigned to the latter as drives. A camera and laser diodes are arranged on the knife carrier of the microtome to detect the shape and positions of the preparation.

Techniques are disclosed for particulate matter (PM) measurement in a medium (such as air) using flat-top intensity laser sheet beam generation. The techniques for generating the laser sheet beam may include nonspecialized optical elements (e.g., aspherical, spherical, biconvex, and/or cylindrical lenses) that are cost-effective, reduce the overall footprint of the system, and also provide for relatively increased power efficiencies compared to conventional techniques. The PM measurement system may use the laser sheet beam generated in combination with a medium flow channel to pass the medium through the laser sheet beam, thereby causing particulates within the medium to scatter light, which can be detected using a light sensor (e.g., a photodetector). The scattered light signals can then be analyzed to match them with corresponding particulate sizes and the amount of signals per particulate size can also be determined to measure the size and count of particulates within the medium.

Using an optical electric field enhancing device including a fine uneven structure made of gold formed on the front surface of a transparent substrate, illumination light of a wavelength in the range from 400 to 530 nm is applied at least to an analyte, positional information of the analyte is detected by a position detection unit disposed on the rear surface side of the optical electric field enhancing device, and excitation light is applied to the detected position by an excitation light application unit. Signal light emitted from the analyte when the excitation light is applied is detected from the rear surface side of the transparent substrate.