Abstract: The present invention relates to the electrophoretic separation of bio-organic molecules using a slab gel electrophoresis apparatus having a pair of spaced, confronting plates defining a multi-lane separation zone adapted to hold a separation medium and an upper loading zone. In one aspect of the invention, at least one of the plates is shaped to provide an expanded loading zone. The plate-to-plate distance within the expanded loading zone is greater than the plate-to-plate width within the separation zone. In another aspect of the invention, a comb is provided with each tooth having a gradual taper beginning at a support member and extending along most of the tooth's longitudinal axis, and a sharp taper beginning immediately beyond the gradual taper and extending to the end of the tooth.

Abstract: Particles are subjected to travelling wave field migration (TWFM) to migrate the particles over an array of microelectrodes. Altered particles are produced by treating original particles in such a way so as to alter their TWFM characteristics and the altered TWFM characteristics are employed for analysis and/or separation of the altered particles. The particles may be cells, bacteria, viruses, biomolecules or plastics microspheres. They may be altered by binding to a ligand such as a metal microparticle via a selective linking moiety such as an antibody/antigen or oligonucleic acid, or be physical or chemical treatments.

Abstract: The present disclosure is directed to a novel apparatus and novel methods for the separtion, characterization, and manipulation of matter. In particular, the invention combines the use of frequency-dependent dielectric and conductive properties of particulate matter and solubilized matter with the properties of the suspending and transporting medium to discriminate and separate such matter. The apparatus includes a chamber having at least one electrode element and at least one inlet and one output port into which cells are introduced and removed from the chamber. Matter carried through the chamber in a fluid stream is then displaced within the fluid by a dielectrophoretic (DEP) force caused by the energized electrode. Following displacement within the fluid, matter travels through the chamber at velocities according to the velocity profile of the chamber. After the matter has transitted through the chamber, it exits at the opposite end of the chamber at a characteristic position.

Abstract: A device is described for electrophoretic molecular separation. This device has a channel formed on a hydrophobic surface thereof. The interior surface of the channel is rendered hydrophilic through successive oxidation and protophilic reactions. A cover extends over the channel to form a conduit which is dimensioned to accept a molecular separation media. The conduit is also positioned for application of an electric current along the length of the interior of the conduit which drives a sample through the molecular separation media. Systems and methods are also described for electrophoretic molecular separation.

Abstract: The present invention is generally directed to improved methods, structures and systems for interfacing microfluidic devices with ancillary systems that are used in conjunction with such devices. These systems typically include control and monitoring systems for controlling the performance of the processes carried out within the device, e.g., controlling internal fluid transport and direction, monitoring and controlling environmental conditions and monitoring results of the processes performed, e.g., detection.

Abstract: A micro injector sample delivery system for charged molecules. The injector is used for collecting and delivering controlled amounts of charged molecule samples for subsequent analysis. The injector delivery system can be scaled to large numbers (>96) for sample delivery to massively parallel high throughput analysis systems. The essence of the injector system is an electric field controllable loading tip including a section of porous material. By applying the appropriate polarity bias potential to the injector tip, charged molecules will migrate into porous material, and by reversing the polarity bias potential the molecules are ejected or forced away from the tip. The invention has application for uptake of charged biological molecules (e.g. proteins, nucleic acids, polymers, etc.) for delivery to analytical systems, and can be used in automated sample delivery systems.

Abstract: The present invention provides for techniques for transporting materials using electrokinetic forces through the channels of a microfluidic system. The subject materials are transported in regions of high ionic concentration, next to spacer material regions of high ionic concentration, which are separated by spacer material regions of low ionic concentration. Such arrangements allow the materials to remain localized for the transport transit time to avoid mixing of the materials. Using these techniques, an electropipettor which is compatible with the microfluidic system is created so that materials can be easily introduced into the microfluidic system. The present invention also compensates for electrophoretic bias as materials are transported through the channels of the microfluidic system by splitting a channel into portions with positive and negative surface charges and a third electrode between the two portions, or by diffusion of the electrophoresing materials after transport along a channel.

Abstract: An apparatus and method for loading samples into a gel of an electrophoretic gel system (EGS). The preferred sample loader includes a membrane having a net negative charge, net neutral charge or no charge (preferably nitrocellulose or nylon) which releasably retains the samples such that the samples are actively released when the membrane is inserted into the gel of an EGS. In one preferred embodiment, the sample loader includes a substrate having a plurality of sample loading areas extending therefrom. In an alternative embodiment, the membrane is substantially thick and serves as its own substrate. In another embodiment, sample inhibiting agents such as hydrophobic ink are formed through the membrane to inhibit the diffusion of samples between sample loading areas. Each sample loading area includes an affixed membrane. In use, one or more samples to be subjected to electrophoretic action are applied to the membrane before the membrane is inserted into a previously polymerized gel.

Abstract: A sample holding device for electrophoresis apparatus according to the present invention wherein a plurality of sample holding capillaries are laid out in an array and are immobilized to the supporting jig. This sample holding device is configured to ensure the lower ends of the capillaries can contact the sample injection portion of the electrophoresis separation part of the electrophoresis apparatus, and provides easy sample injection and prevents the gel capillaries of the electrophoresis separation part from being damaged when sample holding capillaries are filled with gels, thereby allowing repeated use of the gel capillaries of the electrophoresis separation part.

Abstract: Methods for profiling oligosaccharides released from glycoproteins and methods for the electrophoretic separation of high mannose, complex and hybrid oligosaccharides are disclosed. The methods include first providing an analytical sample which includes at least one released oligosaccharide and introducing the sample into an electrophoretic channel containing a separation medium having a pH less than 8 and greater than 2.5. Then applying a sufficiently high electric field causes the released oligosaccharides to migrate and separate within the electrophoretic channel in accordance with their molecular size or charge to mass ratio. Detecting the separated oligosaccharides provides glycoprotein conjugate profiling information. Preferred embodiments include using a separation medium which includes lithium acetate buffer having a pH of about 4.75 and a gel of about 0.4% polyethylene oxide.

Abstract: An electrophoresis apparatus for detecting samples migrating in migration portions includes a plurality of gel separation portions separate from one another and having respective ends disposed along a straight line, a plurality of migration portions equal in number to the gel separation portions and disposed along a straight line following respective ones of the gel separation portions, a light source for generating light which passes through the migration portions, the light propagating along a straight line extending through all of the migration portions, a plurality of optical fibers having respective first ends and respective second ends, the first ends of the optical fibers being disposed facing respective points where the light from the light source passes through respective ones of the migration portions, the optical fibers being equal in number to or greater in number than the migration portions, and an optical detector optically coupled to the second ends of the optical fibers for receiving light fro

Abstract: A novel electrophoresis separation medium comprises polyacrylamide and a dioxane. An electrophoresis separation system comprises a separation channel, the separation channel including the novel separation medium. In a method for electrophoretically separating analytes by introducing analytes into a separation channel, an electric field is applied across the separation channel and the analytes are allowed to electrokinetically migrate within the separation medium. The separation channel comprises the novel electrophoresis separation medium.

Abstract: The present invention provides for techniques for transporting materials using electrokinetic forces through the channels of a microfluidic system. The subject materials are transported in regions of high ionic concentration, next to spacer material regions of high ionic concentration, which are separated by spacer material regions of low ionic concentration. Such arrangements allow the materials to remain localized for the transport transit time to avoid mixing of the materials. Using these techniques, an electropipettor which is compatible with the microfluidic system is created so that materials can be easily introduced into the microfluidic system. The present invention also compensates for electrophoretic bias as materials are transported through the channels of the microfluidic system by splitting a channel into portions with positive and negative surface charges and a third electrode between the two portions, or by diffusion of the electrophoresing materials after transport along a channel.

Abstract: A method for analyzing samples includes forming a plurality of sheath flows of a buffer solution, each of the sheath flows being formed at one end of a respective one of a plurality of capillaries each containing a separation medium, causing samples to migrate through the capillaries into the sheath flows, and detecting the samples in the sheath flows.

Abstract: A method and apparatus for achieving uniform illumination in an electrophoresis apparatus is provided. Uniform illumination allows quantitative measurements of an electrophoresis gel to be made, thus increasing the information which can be obtained from an electrophoretic analysis. Uniform illumination is achieved by scanning the light source, preferably in a trans-illumination mode, across the sample gel in a direction perpendicular to the axis of the source. The light source is comprised of one or more light bulbs placed in a light tray. Variations in light intensity near the source end portions may be minimized using a variety of techniques including extended light bulbs, filters, reflectors, diffusers, or supplemental sources.

Abstract: A microminiature sequencing apparatus and method provide means for simultaneously obtaining sequences of plural polynucleotide strands. The apparatus comprises a microchip into which plural channels have been etched using standard lithographic procedures and chemical wet etching. The channels include a reaction well and a separating section. Enclosing the channels is accomplished by bonding a transparent cover plate over the apparatus. A first oligonucleotide strand is chemically affixed to the apparatus through an alkyl chain. Subsequent nucleotides are selected by complementary base pair bonding. A target nucleotide strand is used to produce a family of labelled sequencing strands in each channel which are separated in the separating section. During or following separation the sequences are determined using appropriate detection means.

Abstract: This invention relates to a method and device for separating charged particles according to their diffusivities in a separation medium by means of a spatially and temporarily varying electric potential. The method is particularly suited to sizing and separating DNA fragments, to generating DNA fragment length polymorphism patterns, and to sequencing DNA through the separation of DNA sequencing reaction products. The method takes advantage of the transport of charged particles subject to an electric potential that is cycled between an off-state (in which the potential is flat) and one or more on-states, in which the potential is preferably spatially periodic with a plurality of eccentrically shaped stationary potential wells. The potential wells are at constant spatial positions in the on-state. Differences in liquid-phase diffusivities lead to charged particle separation. A preferred embodiment of the device is microfabricated. A separation medium fills physically defined separation lanes in the device.

Abstract: Electrophoretic chambers comprising at least a region of surface modification, and methods for their fabrication, are provided. The subject chambers comprise in the region of surface modification, an anchoring polymeric layer interpenetrating the surface of the chamber and an electrophoretic polymeric layer copolymerized with the anchoring polymeric layer. The subject chambers are prepared by sequentially contacting the chamber surface with a first monomer capable of interpenetrating the surface and a second monomer capable of copolymerization with the first monomer, followed by copolymerization of the first and second monomers. The subject devices find use a variety of electrophoretic applications in which entities are moved through a medium under the influence of an applied electric field.

Abstract: The invention relates to a separation procedure for Lp(a) and the various lipoproteins contained in a biological sample by electrophoresis. The present invention is characterized in that the electrophoretic migration of the lipoproteins is carried out under conditions such that the electrophoresis gel and/or the above-mentioned biological sample contains compounds capable of modifying the electrophoretic mobility of Lp(a) differentially with respect to that of the other lipoproteins.

Abstract: A variable rate density gradient electrophoric gel is described which separate LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described.