The invention features devices and methods for the deterministic separation of particles. Exemplary methods include the enrichment of a sample in a desired particle or the alteration of a desired particle in the device. The devices and methods are advantageously employed to enrich for rare cells, e.g., fetal cells, present in a sample, e.g., maternal blood and rare cell components, e.g., fetal cell nuclei. The invention further provides a method for preferentially lysing cells of interest in a sample, e.g., to extract clinical information from a cellular component, e.g., a nucleus, of the cells of interest. In general, the method employs differential lysis between the cells of interest and other cells (e.g., other nucleated cells) in the sample.

A system and method for magnetic density separation of products. The system including a magnet configured to amplify a density gradient in a magnetic liquid for separating the products in the magnetic liquid according to their different density. A plate shape is disposed along a product path where respective products travel through the magnetic liquid. A driving mechanism is configured to drive the plate shape with a reciprocating motion for lowering a static friction of the respective products coming into contact with the plate shape. Accordingly, process continuity can be improved while maintaining a high separation efficiency, in particular by alleviating material build-up and clogging of products at the splitter and other surfaces with minimal disturbance to the process flow.

Methods for separating particles in a ferrofluid, along with apparatus for performing the same, are provided. The method may include introducing the ferrofluid through a separation tube; applying a magnetic field to the separation tube such that a fluid constriction is created within the tube that leads to a density gradient in the fluid with a maximum value (d.sub.max) at some region along the tube; and introducing a plurality of particles into the ferrofluid within the separation tube such that particles having densities greater than d.sub.max flow through the ferrofluid.

Methods for separating particles in a ferrofluid, along with apparatus for performing the same, are provided. The method may include introducing the ferrofluid through a separation tube; applying a magnetic field to the separation tube such that a fluid constriction is created within the tube that leads to a density gradient in the fluid with a maximum value (d.sub.max) at some region along the tube; and introducing a plurality of particles into the ferrofluid within the separation tube such that particles having densities greater than d.sub.max flow through the ferrofluid.

Devices, methods, and systems are provided for extracting particles from a ferrofluid. Such methods may comprise receiving a flow of ferrofluid comprising target particles and background particles and generating a first, focusing magnetic field to focus the target particles towards a capture region. The capture region may capture the target particles and a plurality of background particles. A second, defocusing magnetic field may be configured to remove background particles from the capture region. A detector may be used to detect the target particles bound to the target region.

Devices, methods, and systems are provided for extracting particles from a ferrofluid. Such methods may comprise receiving a flow of ferrofluid comprising target particles and background particles and generating a first, focusing magnetic field to focus the target particles towards a capture region. The capture region may capture the target particles and a plurality of background particles. A second, defocusing magnetic field may be configured to remove background particles from the capture region. A detector may be used to detect the target particles bound to the target region.

Provided are a method of and apparatus for evaluating immune cells using magnetic particles. According to an aspect of the method, magnetic particles may be used to measure interaction of the magnetic particles with immune cells, thereby diagnosing or evaluating a degree of activation of immune cells of a subject or immune-related diseases of the subject. Further, according to an aspect of the apparatus, a phenomenon of interaction of magnetic particles and activated immune cells via endocytosis may be used to collect magnetic particle-immune cell complexes resulting from the interaction with the magnetic particles by applying a magnetic field, thereby effectively isolating the activated immune cells in a short period of time.

Provided are a method of and apparatus for evaluating immune cells using magnetic particles. According to an aspect of the method, magnetic particles may be used to measure interaction of the magnetic particles with immune cells, thereby diagnosing or evaluating a degree of activation of immune cells of a subject or immune-related diseases of the subject. Further, according to an aspect of the apparatus, a phenomenon of interaction of magnetic particles and activated immune cells via endocytosis may be used to collect magnetic particle-immune cell complexes resulting from the interaction with the magnetic particles by applying a magnetic field, thereby effectively isolating the activated immune cells in a short period of time.

Magnetic cell levitation and cell monitoring systems and methods are disclosed. A method for separating a heterogeneous population of cells is performed by placing a microcapillary channel containing the heterogeneous population of cells in a magnetically-responsive medium in the disclosed levitation system and separating the cells by balancing magnetic and corrected gravitational forces on the individual cells. A levitation system is also disclosed, having a microscope on which the microcapillary channel is placed and a set of two magnets between which the microcapillary channel is placed. Additionally, a method for monitoring cellular processes in real-time using the levitation system is disclosed.

Magnetic cell levitation and cell monitoring systems and methods are disclosed. A method for separating a heterogeneous population of cells is performed by placing a microcapillary channel containing the heterogeneous population of cells in a magnetically-responsive medium in the disclosed levitation system and separating the cells by balancing magnetic and corrected gravitational forces on the individual cells. A levitation system is also disclosed, having a microscope on which the microcapillary channel is placed and a set of two magnets between which the microcapillary channel is placed. Additionally, a method for monitoring cellular processes in real-time using the levitation system is disclosed.