Abstract: The present invention relates to methods and apparatuses for the detection of positional freedom of particles used in biological, biochemical, physical, biophysical, and chemical analyses. In particular, the present invention relates to methods and apparatuses which can detect and characterize a population of particles/cells based upon their detected mobility. In one embodiment consistent with the invention, detection of certain cells is based on differences detected in populations of cells that bind to a substrate and those that exhibit weaker binding forces. Initially, cells are settled on the substrate, and in the presence of gravitational, natural thermodynamic pressure fluctuations, and other random or applied forces, some of the particles may exhibit translational movement. Particle movement is detected, and measurements are computed, according to the methods and apparatuses of the present invention, to determine the binding of specific analytes.

Abstract: The present invention relates to methods and apparatuses for the detection of positional freedom of particles used in biological, biochemical, physical, biophysical, and chemical analyses. In particular, the present invention relates to methods and apparatuses which can detect and characterize a population of particles/cells based upon their detected mobility. In one embodiment consistent with the invention, detection of certain cells is based on differences detected in populations of cells that bind to a substrate and those that exhibit weaker binding forces. Initially, cells are settled on the substrate, and in the presence of gravitational, natural thermodynamic pressure fluctuations, and other random or applied forces, some of the particles may exhibit translational movement. Particle movement is detected, and measurements are computed, according to the methods and apparatuses of the present invention, to determine the binding of specific analytes.

Abstract: The present invention relates to producing more densely functionalized indicator cells which along, with other components, can be used to detect the presence or absence of antibodies or antigens, by using the A, B, AB and MNS antigens which have a greater degree of expression than the conventionally used D antigen to label the indicator cells with IgG. The present antigen systems have levels of expression that approach one million antigens per cell, which is in great contrast to the conventional D antigen sites of about 10,000-30,000 antigens per cell. This marked increase in the antigen systems level of expression could produce a boost in the kinetics and the magnitude of the binding of the indicator cell to the solid phase, which improves assay performance.

Abstract: Methods and apparatus for analyzing surface properties of particles are provided. A method for analyzing the surface properties of the particle includes a associating a first particle with a first capture zone having a specific binding affinity for a first chemical species, applying an optical force to the first particle, sensing a response of the first particle to the optical force, and using the sensed response to determine the presence, absence or quantity of the first chemical species on the first particle surface. This process may be repeated in parallel to test multiple particles. In addition to directly testing the surface properties of the particles, the method can be used in direct, indirect and competitive assays to determine the presence, absence or quantity of free or immobilized analytes. A fluidic cartridge with capture zones having avidities that are tuned for the use of optical forces is provided. A software routine for performing the method is also provided.

Abstract: Methods and apparatus for analyzing surface properties of particles are provided. A method for analyzing the surface properties of the particle includes a associating a first particle with a first capture zone having a specific binding affinity for a first chemical species, applying an optical force to the first particle, sensing a response of the first particle to the optical force, and using the sensed response to determine the presence, absence or quantity of the first chemical species on the first particle surface. This process may be repeated in parallel to test multiple particles. In addition to directly testing the surface properties of the particles, the method can be used in direct, indirect and competitive assays to determine the presence, absence or quantity of free or immobilized analytes. A fluidic cartridge with capture zones having avidities that are tuned for the use of optical forces is provided. A software routine for performing the method is also provided.

Abstract: Apparatus for sorting and orienting sperm cells has a pair or walls in confronting relationship forming a flow chamber having inlet, a downstream outlet, and intermediate detector region. The inlet receives first and second spaced apart streams of input fluid and a third stream of sample fluid containing the cells to be sorted. The first and second streams have respective flow rates relative to third stream, such that the third stream is constricted forming a relatively narrow sample stream, so that the cells are oriented parallel to the walls. A detector detects desired cells and a sorter downstream of the detector for sorting the desired cells from the stream.

Abstract: Holographic optical tweezers are used to position charge stabilized colloidal particles within a flow cell. Once the particles are positioned, fixation is accomplished by pumping an electrolyte solution or pH adjusted solution (or a combination of the two) into the sample cell. In the former, the Debye length is reduced and aggregation caused by the van der Waals attraction takes place. In the latter, the surface charge density of the suspension is reduced and aggregation caused by the van der Waals attraction takes place. This technique can be applied multiple times, and allows for the formation of two and three dimensional structures composed of multi-colloid types to be formed on or away from a substrate. The technique relies upon forces acting on virtually all colloidal dispersions making it applicable to a wide variety of colloid types and compositions, such as formation of photonic crystals, colloidal electronics, and bioengineered materials.

Abstract: Nanoscale masking using particles patterned on a substrate include assembling particles into a pattern on a first substrate; contacting the particles with a second substrate; adding blocking molecules while the particles are in contact, such that blocking molecules bind to portions of the second substrate not in contact with the particles; and separating the substrates, yielding a functionalized substrate having blocking molecules bound thereto. Nanoscale printing methods include assembling particles into a desired pattern on a first substrate; contacting a print material with the particles such that at least a portion of the print material binds to the particles on the first substrate; removing the first substrate having particles thereon from unbound print material; contacting the particles having print material bound thereto with a second substrate such that at least a portion of the print material binds to the second substrate; and separating the substrates, yielding a printed substrate.

Abstract: The present invention provides novel methods of cell staining, such as bovine sperm, using electroporation or osmolality treatments at viability-enhancing temperatures. Furthermore, methods of highly efficient cell sorting that are especially suitable in sorting bovine sperm using novel cell staining procedures are also provided.

Abstract: Apparatus for sorting and orienting sperm cells has a pair or walls in confronting relationship forming a flow chamber having inlet, a downstream outlet, and intermediate detector region. The inlet receives first and second spaced apart streams of input fluid and a third stream of sample fluid containing the cells to be sorted. The first and second streams have respective flow rates relative to third stream, such that the third stream is constricted forming a relatively narrow sample stream, so that the cells are oriented parallel to the walls. A detector detect desired cells and a sorter downstream of the detector for sorting the desired cells from the stream.