Methods are provided for separating magnetically responsive beads from a droplet in a droplet actuator. Droplet operations electrodes and a magnet are arranged in a droplet actuator to manipulate a bead-containing droplet and position it relative to a magnetic field region that attracts the magnetically responsive beads. The droplet operations electrodes are operated to control the droplet shape and transport it away from the magnetic field region to form a concentration of beads in the droplet. The continued transport of the droplet away from the magnetic field causes the concentration of beads to break away from the droplet to yield a small, concentrated bead-containing droplet immobilized by the magnet.

Provided herein are methods of 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.

The present invention discloses a time-resolved immunoquantitation test strip for detecting tetrodotoxin (TTX) in shellfish food, which belongs to the technical field of rapid detection of time-resolved immunoassay. In the present invention, fluorescent microspheres are adopted to replace the traditional colloidal gold; the fluorescent microsphere is used for labeling a TTX antibody complex; by utilizing a competitive immunization method, the fluorescent microsphere, serving as a fluorescent probe, is used for immunochromatography; and by reading the fluorescence value of a detection line on a fluoroimmunoassay instrument, the TTX in shellfish samples can be analyzed quantitatively and rapidly. The time-resolved immunoquantitation test strip of the present invention can be used for detecting the content of the TTX in various types of shellfish food quantitatively and rapidly and is strong in specificity and high in sensitivity, wherein when the concentration of the TTX is 0.5-40 ng/mL, the logarithmic value of the concentration has a linear relationship with T/To, a linear equation is: Y=0.57365-0.2668LgX, R.sup.2=0.9940, and the limit of detection can reach 0.047 ng/mL.

The present invention relates to compositions comprising magnetic particles, the methods of using these compositions in processing animal sperm, the resulting sperm and embryo products, and the methods of use of these compositions to increase the efficiency, efficacy and/or speed of cell processing and artificial insemination techniques.

A method for magnetic cellular manipulation may include contacting a composition with a biological sample to form a mixture. The composition may include a plurality of particles. Each particle in the plurality of particles may include a magnetic substrate. The magnetic substrate may be characterized by a magnetic susceptibility greater than zero. The composition may also include a chargeable silicon-containing compound. The chargeable silicon-containing compound may coat at least a portion of the magnetic substrate. The biological sample may include cells and/or cellular structures. The method may also include applying a magnetic field to the mixture to manipulate the composition.

Described herein are immune binding proteins and method for obtaining immune binding proteins from genomic or other sources. Also described herein are nucleic acids encoding the immune binding proteins in which the natural multimeric association of chains is maintained in the nucleic acids and the immune binding proteins made therefrom. For example, nucleic acids encoding antibodies that are amplified from a B-cell using the methods described herein maintain the natural pairing of heavy and light chains from the B-cell. This maintenance of pairing (or multimerization) produces libraries and/or repertoires of immune binding proteins that are enriched for useful binding molecules.

Superparamagnetic nanoparticle-based analytical method comprising providing a sample having analytes in a sample matrix, providing a point of care chip having analytical regions, each of which is a stationary phase having at least one or more sections, labeling each of the analytes with a superparamagnetic nanoparticle and immobilizing the labeled analytes in the stationary phase, providing an analytical device having a means for exciting the superparamagnetic nanoparticles in vitro and a means for sensing, receiving, and transmitting response of the excited superparamagnetic nanoparticles, placing the chip in the analytical device and exciting the superparamagnetic nanoparticles in vitro, sensing, receiving, and transmitting the response of the superparamagnetic nanoparticles, and analyzing the response and determining characteristic of the analytes, wherein the response of the superparamagnetic nanoparticles comprises harmonics. The present invention also provides the hybrid point of care chip and analyzer to be used in the analytical method.

Described is a method and device for detecting an analyte in a sample, comprising bringing a sample comprising a target analyte into contact with magnetisable particles, the particles being coated with binding molecules complementary to the target analyte, resulting in bound and unbound binder complexes, positioning the magnetisable particles, comprising both bound and unbound binder complexes, in proximity to a magnetic field sensor, changing the magnetic field sufficient to release at least a portion of the magnetisable particles, comprising both bound and unbound binder complexes, from their proximity to the magnetic field sensor, and measuring changes in a magnetic signal detected from the net movement, being either translational or rotational movement, of the magnetisable particles relative to the magnetic sensor.

Provided in the present invention are a magnetic nanosphere coated with modified cardiolipin, and manufacturing method thereof. The magnetic nanosphere coated with modified cardiolipin comprises a modified cardiolipin, a biotin derivative, and a streptavidin magnetic bead. The modified cardiolipin is coupled to the biotin derivative via an —NH—CO structure. The streptavidin magnetic bead is a magnetic nanosphere coupled to streptavidin, and the biotin derivative is coupled to the streptavidin.

Methods of detecting a target in a sample are provided. Kits for performing the methods described herein are also provided.