A laser sensor for detecting a particle density includes: a laser configured to emit a measurement beam, an optical arrangement being arranged to focus the measurement beam to a measurement volume, the optical arrangement having a numerical aperture with respect to the measurement beam, a detector configured to determine a self-mixing interference signal of a optical wave within a laser cavity of the laser, and an evaluator. The evaluator is configured to: receive detection signals generated by the detector in reaction to the determined self-mixing interference signal, determine an average transition time of particles passing the measurement volume in a predetermined time period based on a duration of the self-mixing interference signals generated by the particles, determine a number of particles based on the self-mixing interference signals in the predetermined time period, and determine the particle density based on the average transition time and the number of particles.

An optical particle analyser is provided; the analyser comprising: a microfluidic chip comprising: a flow channel for carrying particles; the flow channel arranged between a transparent window and a non-transparent substrate; a light source configured to emit an illumination beam towards the flow channel; wherein the microfluidic chip and the light source are arranged such that, in use, the illumination beam impinges the window at an oblique angle of incidence. By providing the optical particle analyser in this manner, high performance particle analysis may be accurately carried out.

A system is configured to determine a color distribution of an object moving along a flow direction relative to a spatial filter. The light emanating from the object is time modulated according to the mask features of the spatial filter. First and second detectors are arranged to sense the modulated light. The first detector senses light having a first wavelength spectrum and generates a first electrical output signal in response to the sensed light. The second detector light senses light having a second wavelength spectrum and generates a second electrical output signal in response to the sensed light. Signals from the first and second detectors include information about color distribution of the object.

A method for detecting bacteria and determining the concentration thereof in a liquid sample includes the steps of taking an optical section through a container holding a volume of the liquid sample at a predetermined field of view and at a predetermined focal plane depth or angle and after a period of time has elapsed to allow non-bacteria in the sample to settle to the bottom of the container. Since bacteria auto arranges in the liquid sample, forming a lattice-like grid pattern, an optical section through the volume of auto-arranged bacteria may be used to measure the quantity of bacteria residing in that section. A container for holding the liquid sample has particular structure which aids in separating the non-bacteria from the bacteria.

Embodiments of the disclosed subject matter provide an automated method and system to isolate and collect cells using computerized analysis of images of cells and their surroundings obtained from a digital imaging device or system. Embodiments of the disclosed subject matter make use of a microwell array, which can comprise a formed, elastomeric grid of indentations or wells. Many, most, or all of the wells in a microwell array can contain a releasable, microfabricated element, which can be referred to as a raft. Embodiments of the disclosed subject matter provide a system and method for cell collection that includes computerized identification and collection of rafts with isolated single cells or a specific group or groups of cells, eliminating the need for continuous human identification and selection.

The present disclosure provides, among other things, methods and devices for single cells/particle selection and isolation from a sample in a light-curable biomatrix gel. The individual cells or particles are observed by microscopy and manipulated and isolated by accurately controlling the light transmission from a liquid crystal display (LCD) oriented under the sample to provide a detailed image of the sample. In some embodiments, selected cells or particles are then immobilized by curing the biomatrix gel with blue/violet light transmitted from a LED pixel array. In other embodiments, the selected cells or particles of interest are allowed to remain mobile. In either embodiment, the individual cells or particles of interest are segregated from and isolated from the remainder of the sample.

In one aspect, a method of sorting cells in a flow cytometry system is disclosed, which includes illuminating a cell with radiation having at least two optical frequencies shifted from one another by a radiofrequency to elicit fluorescent radiation from the cell, detecting the fluorescent radiation to generate temporal fluorescence data, and processing the temporal fluorescence data to arrive at a sorting decision regarding the cell without generating an image (i.e., a pixel-by-pixel image) of the cell based on the fluorescence data. In some cases, the sorting decision can be made with a latency less than about 100 microseconds. In some embodiments, the above method of sorting cells can have a sub-cellular resolution. In some embodiments, a single radiofrequency shift is employed to separate the optical frequencies while in other such embodiments a plurality of different radiofrequency shifts are employed.

A method for detecting bacteria and determining the concentration thereof in a liquid sample includes the steps of taking an optical section through a container holding a volume of the liquid sample at a predetermined field of view and at a predetermined focal plane depth or angle and after a period of time has elapsed to allow non-bacteria in the sample to settle to the bottom of the container. Since bacteria auto arranges in the liquid sample, forming a lattice-like grid pattern, an optical section through the volume of auto-arranged bacteria may be used to measure the quantity of bacteria residing in that section. A container for holding the liquid sample has particular structure which aids in separating the non-bacteria from the bacteria.

Methods, systems, and devices are disclosed for imaging particles and/or cells using flow cytometry. In one aspect, a method includes transmitting a light beam at a fluidic channel carrying a fluid sample containing particles; optically encoding scattered or fluorescently-emitted light at a spatial optical filter, the spatial optical filter including a surface having a plurality of apertures arranged in a pattern along a transverse direction opposite to particle flow and a longitudinal direction parallel to particle flow, such that different portions of a particle flowing over the pattern of the apertures pass different apertures at different times and scatter the light beam or emit fluorescent light at locations associated with the apertures; and producing image data associated with the particle flowing through the fluidic channel based on the encoded optical signal, in which the produced image data includes information of a physical characteristic of the particle.

The present invention relates to a cell assessment method characterized in including an acquisition step of acquiring an optical path length image of a small cell clump, an extraction step of extracting a cell nucleus region within the acquired optical path length image, a comparison step of comparing an optical path length of an inside and an optical path length of an outside of the extracted cell nucleus region, and an assessment step of assessing whether or not a cell is a stem cell based on the comparison results.