A method for measuring concentrations of blood cell components is provided. The method comprises: obtaining a blood sample from a subject, the blood sample comprising at least one of red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs); mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity; passing the sample mixture through a flow cell; emitting light towards the flow cell; measuring at least one of an amount of light absorbed by the RBCs to obtain an RBC absorption value, an amount of light scattered by WBCs to obtain a WBC scatter value, and an amount of light scattered by PLTs to obtain a PLT scatter value; and determining a concentration of at least one of the RBCs, WBCs, and PLTs present in the sample mixture.

Described herein are apparatuses for analyzing an optical signal decay. In some embodiments, an apparatus includes: a source of a beam of pulsed optical energy; a sample holder configured to expose a sample to the beam; a detector comprising a number of spectral detection channels configured to convert the optical signals into respective electrical signals; and a signal processing module configured to perform a method. In some embodiments, the method includes: receiving the electrical signals from the detector; mathematically combining individual decay curves in the electrical signals into a decay supercurve, the supercurve comprising a number of components, each component having a time constant and a relative contribution to the supercurve; and numerically fitting a model to the supercurve.

A fractionated photoacoustic flow cytometry (PAFC) system and methods for the in vivo detection of target objects in biofluidic systems (e.g., blood, lymph, urine, or cerebrospinal fluid) of a living organism is described. The fractionated system includes a fractionated laser system, a fractionated optical system, a fractionated acoustic system, and combinations thereof. The fractionated laser system includes at least one laser or laser array for pulsing a target object within the circulatory vessel with fractionated focused laser beams. The fractionated optical system separates one or several laser beams into multiple beams in a spatial configuration on the skin above the circulatory vessel of the living organism. The fractionated acoustic system includes multiple focused ultrasound transducers for receiving photoacoustic signals emitted by the target object in response to the fractionated laser beams. The target objects have intrinsic photoacoustic contrast or may be labeled with photoswitchable or spaser-based probes. Fractioned beams may be used also for diagnostics with other spectroscopic methods (e.g., fluorescence, Raman or scattering) and energy sources both coherent and conventional such as lamp and LED in the broad spectral range from 10 Å to 1 cm (e.g., X-ray, UV, visible, NIR or microwaves) in continuous wave and pulse modes.

Disclosed herein include embodiments of a system, a device, and a method for sorting a plurality cells of a sample. A plurality of raw images comprising pixels of complex values in a frequency space can be generated from a plurality of channels of fluorescence intensity data of fluorescence emissions of fluorophores, the fluorescence emissions being elicited by fluorescence imaging using radiofrequency-multiplexed excitation in a temporal space. Spectral unmixing can be performed on the raw images prior to a sorting decision being made.

Methods and systems for operating a flow cytometer can include forward scatter values, side scatter values, and fluorescence intensity values for events of an unstained sample and associating the fluorescence intensity values with forward scatter-side scatter side scatter plot regions. Methods and systems for operating a flow cytometer can also include measuring forward scatter values, side scatter values, and fluorescence intensity values for events of a stained sample, determining forward scatter-side scatter plot locations for the events of the stained sample, and for each event of the stained sample, subtracting the fluorescence intensity value associated with the forward scatter-side scatter plot region that contains the forward scatter-side scatter plot location of the stained sample event from the measured fluorescence intensity value of the stained sample event at that forward scatter-side scatter plot location.

High-throughput methods and systems for using morphological and/or autofluorescence signatures of cells to characterize unknown cell/tissue types within a forensic sample are provided. Machine learning algorithms are used to correlate morphological and/or autofluorescence signatures to characteristics such as cell type.

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.

A device and method of using the device to detect the presence and composition of clots and other target objects in a circulatory vessel of a living subject is described. In particular, devices and methods of detecting the presence and composition of clots and other target objects in a circulatory vessel of a living subject using in vivo photoacoustic flow cytometry techniques is described.

Some embodiments of the methods provided herein relate to sample analysis and particle characterization methods for large, multi-parameter data sets. Frequency difference gating compares at least two different data sets to identify regions in a multivariate space where a frequency of events from a first data set is different than a frequency of events from the second data set according to a defined threshold.