Abstract: The invention relates to a method for tracking the amplification of a sequence of nucleotides in a sample (10). The sample is placed between a light source (12) and an image sensor (16). Under the effect of amplification reagents, mixed with the sample, a nucleotide sequence, called the target sequence, is replicated iteratively, amplifying the target sequence. The method includes the acquisition of an image representative of the formation of a precipitate in the sample under the effect of the amplification, on the basis of which an image of interest is formed. The application of a statistical indicator to the image of interest allows an indicator of the amplification of the target sequence to be determined.

Abstract: A method for observing a sample is provided, including illuminating the sample with a light source and forming a plurality of images, by an imager, the images representing the light transmitted by the sample in different spectral bands. From each image, a complex amplitude representative of the light wave transmitted by the sample is determined in a determined spectral band. The method further includes backpropagation of each complex amplitude in a plane passing through the sample, determining a weighting function from the back-propagated complex amplitudes, propagating the weighting function in a plane along which the matrix photodetector extends, updating each complex amplitude, in the plane of the sample, according to the weighting function propagated.

Abstract: In accordance with embodiments herein, microfluidics systems and methods are described for identifying and/or tracking particles in a droplet. For example, the particle may be a bead, a cell, or any other type of particle. For example, embodiments herein are useful in distinguishing cells from other particles. The microfluidics systems and methods provide the capability to image a large area (e.g., a few square millimeters) within a digital fluidics chamber using interference microscopy, wherein the image of the interference pattern is acquired, instead of an image of the micrometric object itself. The interference pattern results from the incoming light that interferes with the light scattered by the object. In the case of micrometric objects (e.g., cells, bacteria, etc.), the acquired interference pattern may typically be about 100 jum in diameter so that the area can be imaged using a lens-free imaging configuration or using a low magnification lens.

Abstract: This method for detecting at least one particle in a bodily fluid is carried out via a detection system including a light source, a transparent substrate and a photodetector array, the substrate being positioned between the light source and the photodetector. This method includes the placement of a droplet of bodily fluid on the substrate, the illumination of the droplet via the light source, the acquisition of several successive images of the droplet via the photodetector, each image being formed by radiation transmitted by the illuminated droplet and including at least one elementary diffraction pattern, each elementary diffraction pattern corresponding to waves diffracted by a particle upon illumination of the droplet, the identification, via the acquired images of the mobile elementary diffraction patterns, and the counting of moving particles in the droplet, via the identified mobile elementary diffraction patterns.

Abstract: A method for identifying a state of a cell contained in a sample, including: illuminating the sample using a light source by producing an incident light wave propagating toward the sample; then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the matrix-array photodetector such that the matrix-array photodetector is exposed to a light wave resulting from interference between the incident light wave and a diffraction wave produced by each cell; applying a numerical reconstruction algorithm to the image acquired by the matrix-array photodetector, to estimate a characteristic quantity of the light wave reaching the matrix-array detector, at a plurality of distances from the matrix-array photodetector. The value of the characteristic quantity, or its variation as a function of distance, allows the state of the cell to be determined from among predetermined states.

Abstract: A method for identifying a particle contained in a sample, including illuminating the sample using a light source, the light source producing an incident light wave propagating toward the sample, then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the photodetector such that the matrix-array photodetector is exposed to a light wave that is the result of interference between the incident light wave and a diffraction wave produced by each particle. The method further includes applying a numerical reconstruction algorithm to the image acquired by the photodetector, to estimate a characteristic quantity of the light wave reaching the detector, at a plurality of distances from the detector. The variation in the characteristic quantity as a function of distance allows the particle to be identified.

Abstract: The invention relates to a device for observing a sample, including: a light source able to emit an incident light wave that propagates towards a holder able to receive the sample; and an image sensor able to detect a light wave transmitted by the sample when the latter is placed between the light source and the image sensor. The device is characterized in that the light source includes a light-emitting diode that is what is called micron-sized, a light-emission surface of which has a diameter or a largest diagonal smaller than 500 ?m. The invention also relates to a method for observing a sample using such a device.

Abstract: A method for regulating the relative position of an analyte of a sample (16) in relation to a light beam (F) includes the illumination of the analyte of the sample (16) with the light beam (F), capturing by an imaging device (38) a transmission image of the beams scattered by the analyte of the sample (16) in order to establish a diffraction pattern, and modifying the relative position of the analyte of the sample (16) in relation to the light beam (F) according to at least one property of the diffraction pattern.

Abstract: The invention relates to a method for observing a sample, in particular an anatomopathological slide formed from a thin thickness of a sampled biological tissue. It includes a step of illuminating the sample with a light source and acquiring, with an image sensor, an image representing the light transmitted by the sample. The image undergoes holographic reconstruction, so as to obtain a representation, in the plane of the sample, of the light wave transmitted by the latter. The method includes applying an impregnating fluid to the sample, such that the sample is impregnated with said impregnating liquid, said impregnating liquid having a refractive index strictly higher than 1.

Abstract: The invention describes a device allowing the observation of a sample, comprising particles, for example biological particles, by lensless imaging. The sample is disposed against a substrate, the substrate being interposed between a light source and an image sensor. The substrate comprises at least one thin film, extending across a thin film plane, structured so as to form a diffraction grating, designed to confine a part of a light wave emitted by the light source, in a plane parallel to said thin film plane. The device does not comprise magnification optics between the substrate and the image sensor.

Abstract: A method for reconstructing optical properties of a diffracting object immersed in a liquid medium using a reconstruction system that comprises a spatially coherent light source and a matrix photodetector, wherein the liquid medium and the matrix photodetector are separated by a distance along a vertical direction. The method comprises illuminating the liquid medium, measuring (with the matrix photodetector) an intensity of a diffraction pattern transmitted by the illuminated medium along a vertical direction, and reconstructing the optical properties of the diffracting object at a reconstruction height according to a reconstruction algorithm from the measured intensity, wherein the reconstruction height has a value less than that of the distance between the medium and the matrix photodetector along the vertical direction.

Abstract: This method for detecting at least one particle in a bodily fluid is carried out via a detection system including a light source, a transparent substrate and a photodetector array, the substrate being positioned between the light source and the photodetector. This method includes the placement of a droplet of bodily fluid on the substrate, the illumination of the droplet via the light source, the acquisition of several successive images of the droplet via the photodetector, each image being formed by radiation transmitted by the illuminated droplet and including at least one elementary diffraction pattern, each elementary diffraction pattern corresponding to waves diffracted by a particle upon illumination of the droplet, the identification, via the acquired images of the mobile elementary diffraction patterns, and the counting of moving particles in the droplet, via the identified mobile elementary diffraction patterns.

Abstract: A system for detecting optical particles comprises a transparent slide, a composition arranged on the slide, a light source able to light the composition and the slide, and a device for acquiring at least one image of the composition lit by the light source, the transparent slide being positioned between the light source and the acquisition device. The composition comprises water, the particles, a surfactant and a hydrophilic polymer, the particles having a diameter preferably smaller than 10 pm, still more preferably smaller than 1 pm, the surfactant having a concentration preferably at least equal to the critical micellar concentration, the hydrophilic polymer having a boiling temperature higher than that of water.

Abstract: The invention relates to a method for determining a concentration of lipids in a microorganism, in particular a micro-alga, wherein: a sample containing microorganisms is illuminated (101); and a total diffraction pattern (12) of the sample is acquired (102), the total diffraction pattern comprising a plurality of unit diffraction patterns (131; 14A; 14B) each associated with a microorganism. According to the invention, a value of a numerical indicator (In) representative of a dispersion of the light intensity in a zone of interest (13) of the total diffraction pattern is determined (104), and a concentration of lipids (Cx) in the microorganisms is deduced therefrom. The invention also relates to a device for implementing such a method.

Abstract: This method for characterizing a state of adhesion of the particles, is applied via a system comprising a source of spatially coherent light and a photodetector array, the particles being contained in a liquid medium, the liquid medium being delimited by a transparent surface, the particles being able to adhere to said transparent surface. This method comprises the following steps: illuminating (100) the medium with the source of spatially coherent light, acquiring (110) at least one image by the photodetector array, the image being formed by radiation transmitted by the illuminated medium and including at least one elementary diffraction pattern, each elementary diffraction pattern corresponding to waves diffracted by a particle during the illumination of the medium, and computing (120), from at least one acquired image and for at least one particle, a primary indicator characterizing the state of adhesion of the particle to the transparent surface.

Abstract: This method for estimating the quantity of an analyte contained in a liquid includes the following steps: introducing the liquid into a fluid chamber; mixing the liquid with a bi-specific reagent, the bi-specific reagent being configured for grafting on both a particle and an analyte present in the liquid; lighting the fluid chamber using an excitation beam emitted by a light source, the beam extending through the fluid chamber; acquiring at least one image using a matrix photodetector, the image being formed by radiation transmitted by the lighted fluid chamber; and estimating, from at least one acquired image, the quantity of said analyte in the liquid.

Abstract: The method is provided for characterizing agglomeration of particles in a liquid containing an analyte, including introducing liquid into a fluid chamber; mixing the liquid with a bifunctional reagent, lighting the fluid chamber using an excitation light beam extending through the fluid chamber in a longitudinal direction (X); acquiring at least one image using a matrix photodetector, each image including pixels (In(x,y), x,y representing the coordinates of a pixel of an image, the image (I(x,y)) being formed by radiation transmitted by the lighted fluid chamber; and calculating from at least one acquired image (I(x,y)), at least one indicator (Ind2) characterizing the particle agglomeration. The photodetector can be positioned less than 1 cm from the fluid chamber, and during the calculation step, the calculated indicator (Ind2) is representative of the intensity of the pixels of the image. The method advantageously allows for charactering the agglomeration of particles in a liquid.

Abstract: A method of discriminating a living cell from a dead cell, and a device for implementing the method, the method including: using a lens-free imaging device to acquire a diffraction figure corresponding to a cell; and determining a light intensity on a central area of an elementary diffraction figure associated with the cell. It can thus be determined if the studied cell is a living cell or a dead cell.

Abstract: The method according to the invention is capable of characterizing a variation in the speed of particles or agglomeration of particles, the particles, such as blood particles, being contained in a liquid (12). The characterization method includes the following steps: introducing the liquid (12) into a fluid chamber (14); lighting the fluid chamber (14) using an excitation light beam (18) emitted by a light source (16), the light beam (18) extending through the fluid chamber (14) in a longitudinal direction (X); acquiring at least one image using a matrix photodetector (20), the image being formed by radiation transmitted by the lighted fluid chamber (14); and calculating, from at least one acquired image, at least one indicator characterizing the variation of the speed or agglomeration of the particles. During the acquisition step, the photodetector (20) is positioned at a distance (D2) smaller than 1 cm from the fluid chamber (14) in the longitudinal direction (X).

Abstract: A method for regulating the relative position of an analyte of a sample (16) in relation to a light beam (F) includes the illumination of the analyte of the sample (16) with the light beam (F), capturing by an imaging device (38) a transmission image of the beams scattered by the analyte of the sample (16) in order to establish a diffraction pattern, and modifying the relative position of the analyte of the sample (16) in relation to the light beam (F) according to at least one property of the diffraction pattern.