The invention relates the use of single particle light scattering, preferably interferometric scattering microscopy (also referred to herein as iSCAT), to measure the concentration of a particle in a solution. The invention furthermore relates to the use of light scattering to detect lipoprotein particles in a sample, and to related diagnostic and treatment methods.

A method for detecting the concentration of particles in a fluid is disclosed. The method comprises the steps of: S1: introducing a pure fluid into a detection device to obtain a scatter background noise value U noise output by the detection device; S2: introducing a fluid to be detected into the detection device, obtaining scatter signals output by the detection device, and obtaining voltage signals of standard particles; S3: sampling signals of the fluid in a certain period of time, extracting effective signals, carrying out threshold value analysis on the effective signals Ux obtained by sampling, and obtaining the number of particles present in the period of time; and S4: obtaining the concentration of the particles in the fluid according to the number of particles in S3. According to this method, the accuracy in calculation of the concentration of particles in a fluid can be effectively improved.

A particle counter and classification system and method wherein a first stage magnetometer sensor subsystem for the fluid is tuned to detect and determine the size of ferrous and/or conducting particles in the fluid above a predetermined size. A pump is configured to drive a volume of the fluid through the first stage magnetometer sensor subsystem. A processing subsystem is responsive to the first stage magnetometer sensor subsystem and is configured to count the number of ferrous and/or conducting particles above the predetermined size based on the output of the first stage magnetometer sensor subsystem and to determine and report the concentration of the ferrous and/or conducting particles above the predetermined size as a function of the size of the particles, their number, and the volume of the fluid.

A method of rapid functional analysis of cells is provided. A body fluid sample is introduced into a reservoir of a measurement instrument. A living cell is loaded directly from the body fluid sample into a channel of the measurement instrument in the absence of long-term cell culturing, cell passaging, and application of long-term drug pressure to cells. A functional biomarker of the living cells is measured while the living cell flows through the channel. The functional biomarker measured may be mass accumulation rate (MAR) or mass change. The measurement instrument may be a suspended microchannel resonator (SMR).

Particle detection device comprising a support, a platform for receiving particles, four beams suspending the platform from the support, such that the platform can be made to vibrate, means for making said platform vibrate at a resonance frequency, means for detecting the displacement of the platform in a direction of displacement. Each beam has a length l, a width L and a thickness e and the platform has a dimension in the direction of displacement of the platform and in which in a device with out of plane mode l10L and the dimension of each beam in the direction of displacement of the platform is at least 10 times smaller than the dimension of the platform in the direction of displacement.

The invention provides devices and methods for measuring how living cells function. The measurements can be made from tissue biopsy samples to measure functional properties of living cells from a solid tumor. After measuring a functional property of a cell, the cell remains alive and is available for other subsequent analyses. In certain aspects, the invention provides a method for measuring a cancer marker. The method includes obtaining a tissue sample comprising living cells, disaggregating the tissue sample and loading individual live cells into an input channel of a measurement instrument, and flowing the live cells through the measurement instrument to measure a functional property of the live cells.

Methods of calibration are provided. A method comprises introducing a material with cell-like properties and a known mass into a sensor on a measurement instrument to generate a calibration reading and adjusting an output module of the measurement instrument until the measurement instrument calibrates to the known mass for the material.

A method of partitioning droplets from a fluid reservoir containing particles provides a non-Poissonian distribution of dispensed droplets containing a desired number of particles. The method constitutes a method of operating an electrowetting on dielectric (EWOD) device including the steps of: inputting a fluid reservoir containing particles into the EWOD device; performing an electrowetting operation to dispense a plurality of dispensed droplets from the fluid reservoir; interrogating each droplet with a detector and determining whether each dispensed droplet has a desired number of particles; selecting dispensed droplets that contain the desired number of particles and performing an electrowetting operation to move the selected dispensed droplets to a reaction area on the EWOD device; and rejecting dispensed droplets that do not contain the desired number of particles and performing an electrowetting operation to move the rejected dispensed droplets to a holding area on the EWOD device that is different and spaced apart from the reaction area. The selected droplets may be combined, including with or without a portion of the rejected droplets and/or additional reagent, into a larger reaction droplet that may be used in subsequent reaction protocols.

Electromechanical detection device, particularly for gravimetric detection, and method for manufacturing the device. The electromechanical detection device includes a support including a face defining a plane, at least one beam that can move relative to the support, and means of detecting beam displacement, outputting a signal that depends on the displacement. The beam is anchored to the support through an end and is approximately perpendicular to the plane, and the other end of the beam includes at least one reception zone that can receive one or several particles causing or modifying displacement of the beam, in order to determine at least one physical property of the particle(s) from the signal. According to the invention, the detection means are located between the reception zone and the support.

A method for obtaining the absorption position, mass and rigidity of a particle deposited on the surface of a resonator based on the relative change in the resonance frequency of said resonator in 3 or 4 flexural vibration modes. The rigidity of the particles is of great interest in the study of cells and other biological compounds that change state without significantly changing the mass.