Systems, methods, and apparatus for differential phase contrast microscopy by transobjective differential epi-detection of forward scattered light are provided. In some embodiments, a microscope objective comprises: a housing with mounting threads at a second end; optical components defining an optical axis, comprising: an objective lens mounted at a first end, configured to collect light from a sample placed in a field of view, the plurality of optical components create a pupil plane at a first distance along the optical axis at which rays having the same angle of incidence on the objective lens converge at the same radial distance from the optical axis; a photodetector within the housing offset from the optical axis at a second distance along the optical axis; and another photodetector within the housing at second distance along the optical axis and offset from the optical axis in the opposite direction from the first photodetector.

A flow cytometer of a blood analyzer including a transverse-electric (TE) laser diode, a flow cell, a quarter wave plate (QWP), a plurality of lenses, and a side scatter detector. The TE laser diode is configured to output a laser beam along an optical axis and has a fast axis full width at half maximum (FWHM) divergence of from about 16 degrees to about 25 degrees. The QWP is disposed along the optical axis between the TE laser diode and the flow cell and configured to circularly polarize the laser beam. The plurality of lenses is disposed between the TE laser diode and the flow cell and configured to focus the laser beam at the flow cell.

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.

Methods of classifying flow cytometer data are provided. Methods of interest include receiving a first gate and flow cytometer data, expanding the first gate to generate a second gate, and determining sets of flow cytometer data encompassed by each of the first gate and the second gate to classify the flow cytometer data. In embodiments, methods also involve recording a subset of the classified flow cytometer data and optionally adjusting the first and/or second gates based on the recorded data. In some cases, the subject methods include sorting particles associated with the classified flow cytometer data based on the first and second gates. Systems and computer-readable storage media for practicing the invention are also provided.

A device for detecting (D) at least one predetermined particle (P) includes an interferometric element (EI) arranged so as to be illuminated by an incident radiation (L.sub.in) and comprising at least one so-called thin layer (CM) disposed on top of a so-called substrate layer (Sub), the particle being attached to a surface (Sm) of the thin layer, the interferometric element (EI) forming a Fabry-Pérot cavity with or without attached particle P; a matrix sensor (Det) adapted to detect an image comprising a first portion (P.sub.1) deriving from the detection of the incident radiation transmitted (L.sub.TBG) by the interferometric element alone and a second portion (P.sub.2) deriving from the detection of the incident radiation transmitted (L.sub.TP) by the interferometric element and any particle (O, P) attached to a surface (Sm) of the thin layer; a processor (UT) linked to the sensor and configured: to calculate, as a function of wavelengths of the incident radiation λ.sub.i i∈[1,m], the variation of intensity of at least one first pixel of the first portion, called first variation (F.sub.BG) and of at least one second pixel of the second portion, called second variation (F.sub.P), to determine a trend, as a function of the wavelengths of the incident radiation λ.sub.i i∈[1,m], of a phase shift ϕ.sub.i between the first variation and the second variation; to detect the attached particle when the phase shift ϕ.sub.i is not constant as a function of the wavelengths of the incident radiation λ.sub.i i∈[1,m].

A portable air quality monitoring device is disclosed that can identify the type of particles in the air. This device takes images of particles in the air and compares them with a library of particles in its memory to identify the type of particles. The device has a housing that draws ambient air into the system and takes microscopic images of the flowing particles and droplets using flash photography. The device can be stand alone or can connect to the back of a mobile phone and use the mobile phone camera and light. People can upload their local air quality data online for all to see the local air quality.

The apparati, methods, and computer program products disclosed herein can be used to nondestructively detect undissolved particles, such as glass flakes and/or protein aggregates, in a fluid in a vessel, such as, but not limited to, a fluid that contains a drug.

An apparatus for nondestructive detection of transparent or reflective objects in a vessel includes an imager configured to acquire data that represent light reflected from spatial locations in the vessel as a function of time, a memory operably coupled to the imager and configured to store the data, and a processor operably coupled to the memory and configured to detect the objects based on the data by (i) identifying a respective maximum amount of reflected light, over time, for each location in the spatial locations based on the data representing light reflected from the spatial locations as a function of time, and (ii) determining a presence or absence of the objects in the vessel based on the number of spatial locations whose respective maximum amount of reflected light, over time, exceeds a predetermined value.

To provide an adjusting method of a positional relationship between a flow path position and a light irradiation position.

The present technology provides a position adjusting method provided with an imaging step of imaging, while moving a flow path through which a microparticle is able to flow in an optical axis direction, the flow path in a plurality of positions in the optical axis direction, a movement step of moving the flow path in the optical axis direction on the basis of a focus index for each of a plurality of images acquired at the imaging step, and an adjustment step of specifying a feature position of the flow path from an image of the flow path in a position after movement at the movement step, and adjusting a positional relationship between the feature position and a reference position in a direction perpendicular to the optical axis direction.

Disclosed is an optical trap calibration apparatus and method based on variation of electric field by optical imaging of a nanoparticle. By means of a direct optical imaging method, a linear nanoparticle equilibrium position displacement under the action of a constant electric field is measured to realize calibration, thereby avoiding the introduction of error signals, and improving the reliability of differential calibration. The specific calibration method and apparatus of the present invention are not only suitable for calibration of electric field quantity, but also suitable for the calibration of other magnetic forces and the like. By means of the accurate calibration of mechanical quantity in the present invention, the development and application of the vacuum optical trap sensing technology can be promoted.