Systems and methods are provided for counting particles in a fluid flow. In an aspect, coordinates of particles are obtained from video data of particles in a fluid, the video data made up of a sequence of image frames. The particle positions are linked in each pair of consecutive image frames of the video data. The linked particle positions are used to calculate particle trajectories through sequential image frames of the video data, and the particles are counted based on the particle trajectory. In another aspect, the particle positons within each image frame are transformed to estimated positions within a common coordinate frame. The estimated particle positions of a particle are grouped into a cluster center, and the particle count is calculated based on the cluster centers.

Aspects of the present disclosure include methods for characterizing particles of a sample in a flow stream. Methods according to certain embodiments include detecting light from a sample having cells in a flow stream, generating an image of an object in the flow stream in an interrogation region and determining whether the object in the flow stream is an aggregate based on the generated image. Systems having a processor with memory operably coupled to the processor having instructions stored thereon, which when executed by the processor, cause the processor to generate an image of an object in a flow stream and to determine whether the object is an aggregate are also described. Integrated circuit devices (e.g., field programmable gate arrays) having programming for practicing the subject methods are also provided.

Fluidic resistance units are provided. Fluidic resistance units of interest include a plurality of valves and a plurality of resistors, where each resistor in the plurality of resistors is fluidically coupled to and co-located with a different valve in the plurality of valves. In one embodiment, fluidic resistance units include an inlet for receiving fluid, a valve line fluidically coupled to the inlet, a resistor line fluidically coupled to the inlet, a plurality of connectors fluidically coupling the valve line to the resistor line, and an outlet for emitting fluid. Valve lines of interest include a series of fluidically coupled valves, and resistor lines of interest include a series of fluidically coupled resistors. Methods and flow cytometers involving the subject fluidic resistance units are also provided.

Methods and apparatuses to detect particles in dense particle fields are described. A time varying signal is partitioned into a plurality of segments. Parameters are determined from the segments. The time varying signal is parsed into a plurality of individual particle signal components based on the plurality of parameters.

Aspects of the present disclosure include methods for detecting events in a flow cytometer. Also provided are methods of detecting cells in a flow cytometer. Other aspects of the present disclosure include methods for determining a level of contamination in a flow cell. Computer-readable media and systems, e.g., for practicing the methods summarized above, are also provided.

Provided is a cell detection method which makes it possible to effectively and accurately perform gene analysis only on target cells. The cell detection method includes a sorting step of obtaining first information derived from cells in a sample solution by using a flow cytometry method and sorting target cells into a container having arrays of wells each having an opening based on the first information, an imaging step of imaging the cells sorted into the container, and a determination step of obtaining second information derived from cells based on the image of the cells captured by the imaging step and determining cells to be analyzed from the sorted cells.

Provided are methods of detecting, assessing or determining the presence or absence of particles, such as bead particles, present in a cell composition. Also provided are articles of manufacture and kits for use in the methods.

Aspects of the present disclosure include methods for detecting events in a flow cytometer. Also provided are methods of detecting cells in a flow cytometer. Other aspects of the present disclosure include methods for determining a level of contamination in a flow cell. Computer-readable media and systems, e.g., for practicing the methods summarized above, are also provided.

A method of choosing which undesired cell to destroy in a multi-cell fluorescent event includes detecting fluorescence of cells, converting photons detected in the fluorescence into an analog voltage output signal, and identifying at least two discernable peaks associated with the cells. By looking solely at properties measured within the multi-cell fluorescent event, a decision of which cell to target for elimination can be made. Using this method with large population sizes can result in an effective sex skewed product. The sex skewed product can, for example, be formed from bull semen which is then later used to inseminate cows which results in an increased likelihood of giving birth to female cattle.

Aspects of the present disclosure include methods for detecting events in a flow cytometer. Also provided are methods of detecting cells in a flow cytometer. Other aspects of the present disclosure include methods for determining a level of contamination in a flow cell. Computer-readable media and systems, e.g., for practicing the methods summarized above, are also provided.