The invention relates to a method and system for characterizing particles using a flow cytometer comprising detecting radiated light from the particles using two or more detectors positioned to allow for the detection in two or more angular directions and generating a waveform, as a digital representation for the detected radiated light for each of said angulation direction. The waveforms are transformed using one or more basis functions to obtain one or more coefficients characterizing the waveform. The one or more coefficients characterizing the waveform preferably correspond to properties of the particle(s), thereby enabling analysis of physical properties of the particles (such as size, shape, refractive index) or biological properties of the particles (such as cell type, cell cycle state or localization or distribution of molecules within the cell and/or on the cell surface). In preferred embodiments the method and system are used for a label-free sorting of particles, in particular biological cells.

Metal oxide gel particles, may be prepared with a desired particle size, by preparing a low-temperature aqueous metal nitrate solution containing hexamethylene tetramine as a feed solution; and causing the feed solution to flow through a first tube and exit the first tube as a first stream at a first flow rate, so as to contact a high-temperature nonaqueous drive fluid. The drive fluid flows through a second tube at a second flow rate. Shear between the first stream and the drive fluid breaks the first stream into particles of the metal nitrate solution, and decomposition of hexamethylene tetramine converts metal nitrate solution particles into metal oxide gel particles. A metal oxide gel particle size is measured optically, using a sensor device directed at a flow of metal oxide gel particles within the stream of drive fluid. The sensor device measures transmission of light absorbed by either the metal oxide gel particles or the drive fluid, so that transmission of light through the drive fluid changes for a period of time as a metal oxide gel particle passes the optical sensor. If a measured particle size is not about equal to a desired particle size, the particle size may be corrected by adjusting a ratio of the first flow rate to a total flow rate, where the total flow rate is the sum of the first and second flow rates.

A method includes illuminating a drop with a pulse of light from a light source. A duration of the pulse of light is from about 0.0001 seconds to about 0.1 seconds. The method also includes capturing an image, video, or both of the drop. The method also includes detecting the drop in the image, the video, or both. The method also includes characterizing the drop after the drop is detected. Characterizing the drop includes determining a size of the drop, a location of the drop, or both in the image, the video, or both.

A method of determining particle size distribution from multi-angle dynamic light scattering data, comprising: obtaining a series of measured correlation functions g(θ.sub.i) at scattering angles θ.sub.i; and solving an equation comprising $\left[\begin{array}{c}g\left({\theta }_1\right)\\ \mathrm{.Math.}\\ g\left({\theta }_n\right)\end{array}\right]=\left[\begin{array}{c}{\alpha }_{1}K\left({\theta }_1\right)\\ \mathrm{.Math.}\\ {\alpha }_{n}K\left({\theta }_n\right)\end{array}\right]x,$
wherein: K(θ.sub.i) is the instrument scattering matrix computed for angle i, x is the particle size distribu

Provided are a raw material particle size distribution measuring apparatus and a particle size distribution measuring method. Also provided is a porosity measuring apparatus. The raw material particle size distribution measuring apparatus includes: a coarse particle measuring device that acquires information indicating the particle size distribution of the coarse particles; a fine particle measuring device that acquires information indicating the particle size distribution of the fine particles; and an arithmetic device that computes the particle size distribution of the coarse particles using the information indicating the particle size distribution of the coarse particles, computes the particle size distribution of the fine particles using the information indicating the particle size distribution of the fine particles, and computes an overall particle size distribution of the raw material using the particle size distribution of the coarse particles and the particle size distribution of the fine particles.

Methods and apparatuses to image particles are described. A plurality of illuminating light beams propagating on multiple optical paths through a particle field are generated. The plurality of illuminating light beams converge at a measurement volume. A shadow image of a particle passing through a portion of the measurement volume at a focal plane of a digital camera is imaged. Shadow images of other particles in the particle field are removed using the plurality of illuminating light beams.

Devices, methods, kits and means for easy, accurate, and fast estimation of soil microbial load, including fungal load, and fungal to bacterial ratio are described. The methods include extracting soil biomass into an extraction fluid to obtain a soil extract and detecting the fungal fraction, the bacterial fraction, and the fungal to bacterial ratio in the soil extract. The devices typically include microBIOMETER®, devices for particle size discrimination, and devices for absorbance and reflectance detection. The difference in microscopic sizes or spectroscopic absorbance of the fungal particles relative to those of the bacterial particles is used to compute the contribution of each type of particle to the biomass. In one example, the relative coverage of the microBIOMETER® device membrane by the fungal and/or bacterial particles can be measured by and then calculated using a cell phone camera and application.

These methods and apparatus improve the determination of particle characteristics from information derived from light scattered by particles.

Devices, methods, kits and means for easy, accurate, and fast estimation of soil microbial load, including fungal load, and fungal to bacterial ratio are described. The methods include extracting soil biomass into an extraction fluid to obtain a soil extract and detecting the fungal fraction, the bacterial fraction, and the fungal to bacterial ratio in the soil extract. The devices typically include microBIOMETER®, devices for particle size discrimination, and devices for absorbance and reflectance detection. The difference in microscopic sizes or spectroscopic absorbance of the fungal particles relative to those of the bacterial particles is used to compute the contribution of each type of particle to the biomass. In one example, the relative coverage of the microBIOMETER® device membrane by the fungal and/or bacterial particles can be measured by and then calculated using a cell phone camera and application.

Time multiplexing an electromagnetic trap beam may be used to generate trap shapes/geometries to trap one or more particles with one electromagnetic beam by directing the electromagnetic beam at a pattern of different locations with sufficient rapidity to form an effective shape/geometry. Additionally, multiplexing an electromagnetic trap beam may be used to shutter trapping electromagnetic radiation to protect a viewer, use the same beam for multiple functions, move and organize particles, and generate illumination effects.