Sandwich separation is based on forming a sandwich complex with a magnetic bead, buoyant bead, and a target. Once a sandwich formation is created, the sandwich can be separated using its dual physical properties, namely magnetism and buoyancy. Sandwich separation is highly specific, allows for removal of the beads that do not have any attached target, and reduces the number of background beads. Sandwich separation can also be used to allow for target detection in raw specimen. Also, improvement of detection capability is accomplished by performing AMBR measurements on a solid interface, where the rotational period speeds up and allows for dramatically reduced time-to-result.

A device for detecting at least one analyte in a liquid sample generally comprises (i) a support having a chamber for receiving a biological fluid (e.g., milk) therein, wherein said chamber is an elongate chamber having a length axis; (ii) a (stationary or movable) carrier (in some embodiments in the form of an end cap, or connected to an end cap; in other embodiments in the form of an agitator in said elongate chamber).

Embodiments of the present invention are directed toward devices, systems, and method for conducting nucleic acid purification and quantification using sedimentation. In one example, a method includes generating complexes which bind to a plurality of beads in a fluid sample, individual ones of the complexes comprising a nucleic acid molecule such as DNA or RNA and a labeling agent. The plurality of beads including the complexes may be transported through a density media, wherein the density media has a density lower than a density of the beads and higher than a density of the fluid sample, and wherein the transporting occurs, at least in part, by sedimentation. Signal may be detected from the labeling agents of the complexes.

A device is provided. The device comprises a casing comprising an interior, a first opening, and a second opening; and a porous carrier comprising a sample-receiving zone and a target analyte-binding zone. The porous carrier defines a first fluid pathway that extends from the sample-receiving zone to the target analyte-binding zone. At least portion of the porous carrier is disposed in the interior of the casing. A second fluid pathway comprising a central axis extends through the casing from the first opening and the second opening, the second fluid pathway intersecting the porous carrier at the target analyte-binding zone. The central axis is oriented orthogonally with respect to the porous carrier. Methods of using the device to detect a target analyte are also provided.

A system and method for evaluation of an interaction between an analyte in a fluid sample and a ligand immobilized on a sensor surface of a biosensor is provided. In one example, the system includes a plurality of needles, each being arranged to inject a fluid sample to one of sensor surfaces or detection spots. A plurality of fluid samples, each containing known concentrations of analyte, is provided. The plurality of fluid samples may be divided into at least two groups, each group having a number of fluid samples corresponding to the number of needles. The system and method is configured to perform the injections without intermediate regeneration or renewal of the immobilized ligand. Software for performing the steps of the method and a computer readable medium for storing the software are also provided.

Fluidic devices and methods are provided.

An immunochromatographic detection device adapted for detecting an analyte in a specimen includes a surface-modified cellulose membrane, a detection unit, and a substrate. The surface-modified cellulose membrane includes opposite top and bottom surfaces, cellulose fibers, and an anti-biofouling acrylic copolymer that is bonded to the cellulose fibers. The detection unit is disposed on the top surface of the cellulose membrane, is configured to interact with the specimen, and includes a diffusion layer, a capturing layer, a detection layer, a control line layer, and an absorbent layer. The substrate is disposed on the bottom surface of the surface-modified cellulose membrane.

A novel detection system and method is presented, where a two-bead receptor method is used for capturing pathogens, with one type of bead being magnetic and having a size of 3 microns or smaller, and the other type being polymeric and having a size of 3 microns or larger. The first type is used to concentrate a pathogen; the latter is used to create a detectable signal. Fast sensitive detection is achieved by collecting the optical signal created by the distortion of a homeotropically aligned chromonic azo dye in the presence of captured pathogens.

The invention provides compositions, systems and methods for detecting multiple analytes from a sample.

A biosensor molecule comprises: a protease amino acid sequence; at least one sensor comprising at least one sensor amino acid sequence which is responsive to at least one target molecule; and an inhibitor of the protease activity of said protease amino acid sequence; wherein the biosensor is switchable from a protease active to a protease inactive state, or from a protease inactive to a protease active state when said sensor responds to said target molecule. The biosensor protease may be a protease of a virus such as a Potyvirus or a Flavivirus wherein the inhibitor is an autoinhibitory peptide derived from the virus. The biosensor may respond to the target molecule allosterically or may be cleaved by a target protease molecule.