Abstract: Improved methods, reagents, and kits for quantitation of HLA-DR expression on peripheral blood cells, particularly peripheral blood monocytes, are presented. Inclusion of a lysosomotropic amine, such as chloroquine, during staining stabilizes HLA-DR expression, and use of a novel anti-CD14 conjugate, anti-CD14-PerCP/CY5.5, permits the ready discrimination of monocytes. The improved methods, reagents, and kits may be used to assess immune competence, and to direct and monitor immunostimulatory therapies in septic patients exhibiting monocyte deactivation.

Abstract: This invention presents improved methodology for identification of nucleated cells in flow cytometric analysis when immunofluorescent dyes are also used. Briefly, in the method nucleic acids are stained with a fluorescent dye which can then be used to identify the nucleated cells by measurement of fluorescence on a flow cytometer. The improvement presented by this invention is the use of a saturating (or near saturating) amount of a nucleic acid dye, or mixture of dyes, which gives low fluorescence at excitation conditions, so as not to greatly interfere with the signals of the immunofluorescent dyes.

Abstract: An apparatus and method of use for assaying cellular motility in response to a concentration gradient of a chemotactic agent. Generally, the apparatus includes a chamber having a region for receiving a biological sample containing cells of interest and, spaced apart from such region, another region for receiving a chemotactic agent. Between these regions, a concentration gradient of chemotactic agent is established. The apparatus further includes an optical system for detecting and mapping the positions of individual cells responsive to such concentration gradient. Means for processing and analyzing the collected data are also provided. Motility determinations may be made on purified or unpurified samples. Single-site assay devices and multi-site, high-throughput assay devices are disclosed.

Abstract: An apparatus and method are disclosed to wash blood cells in a discrete manner that is compatible with automated sample preparation systems. The test tube containing the cells to be washed is mounted on a rotatable spindle. The spindle includes central passageways for the introduction of wash fluid and air into the test tube, and radial exit passageways at the bottom of the spindle. The test tube is first spun about its vertical axis to centrifuge cells against the inner wall of the test tube. A vacuum is then applied to the exit passageways so cell supernatant is aspirated out through the exit passageways. Wash fluid is then introduced into the test tube, and aspirated out through the exit passageways, thereby washing the cells. Rotational acceleration and deceleration of the test tube then resuspends the cells in wash fluid.

Abstract: Method and reagents for analysis of nucleic acid sequences is disclosed. In this method a plurality of padlock probes is provided. Each padlock probe may hybridize to a locus on a target nucleic acid under hybridization conditions. If a targeted variant is present at the locus, the padlock probe may be ligated to form an amplification target circle. The amplification target circle acts as a template for production of tandem-sequence DNA. The tandem-sequence DNA may then be digested into non-tandem detection fragments which are subsequently separated and detected. The plurality of padlock probes are designed such that ligation of the probes, amplification of the target circle, and digestion of the tandem-sequence DNA subsequently produced, and detection may all be effected with the same set of reagents.

Abstract: A capillary valve, connector and router where one or more cylindrical fibers, which may be capillaries, plugged capillaries, optical fibers, or the like, including at least one capillary tube are contained in a first cylindrical bundle of fibers that terminates at a first face. A second cylindrical bundle of fibers also containing one or more fibers including at least one capillary tube terminates in a second face abutting the first face. A fastener or adapter holds the members together with faces in mutually biased alignment, allowing relative rotation of the two cylindrical bundles which terminate in rotatable ferrules. Various functions achieved by rotation include a zero dead volume slide valve, a fluid router and a manifold. The fibers in each sleeve are preferably of uniform size for close symmetrical packing, but could be of disparate sizes, allowing connection of macroscale tubes to capillary tubes.

Abstract: A method and assay system for the displacement of background from the area surrounding target material allows more sensitive detection. The invention is for use with a system in which specific targets localized at a depth within a container are detected in a liquid containing background material that produces an optical background signal. A displacement liquid is introduced that has a density selected to form a layer encompassing the target material and displacing the material that produces the background signal. The layer of the displacement liquid is sufficient to displace background material from a depth exceeding the depth of field of the detection system. The target material is then optically detected at the depth containing the target material with diminished background allowing greater detection sensitivity.

Abstract: A sample substrate for use in a fluorescence imaging system includes a rigid base with a specularly reflective surface, typically metal, on which is deposited a transparent coating layer. The coating layer has a thickness selected so that a particular fluorescence excitation wavelength, corresponding to a specified fluorescent constituent to be sought in sample material, has an optical path from the top of the coating layer to the reflecting surface in the base of substantially an odd multiple of one-quarter wavelength, so that the standing wave of the fluorescence excitation wavelength of light incident on the substrate has an antinode located at or near where sample material would be disposed on top of the coating layer. This maximizes fluorescence excitation of the sample on the reflective substrate. The transparent coating layer may be a dielectric material (e.g. silica) or may be a multilayer structure with a top layer of biologically active material for binding a specified sample constituent.

Abstract: The apparatus and method of the present invention disclose a system in which multiple injections may be made into a capillary array. The injections are spaced in time with each injection followed by an interval of electrophoresis. Once all samples are loaded into the capillaries, continuous electrophoresis and detection is used to separate and detect target compounds within the sample. The interval between injections is matched to the target compound migration rate to be sufficient to allow the target compounds to be detectably separated when the compounds reach the detector.

Abstract: A method and apparatus for autofocus on a target layer contained within a microplate well is provided. The instrument is capable of optically sensing a reference point on the underside of a microplate. This reference point is then used to focus light onto a target layer within the microplate well, the target layer having a location that is in defined relation to the reference point. The reference point is either a surface of the bottom of the microplate well or is an optically detectable mark on the underside of the microplate. In an alternate embodiment, a light position sensitive detector is used to enable deterministic autofocus for a plurality of wells on a microplate.

Abstract: The present invention describes a method and apparatus utilizing a capillary coating of linear and crosslinked polymers and copolymers of acrylamidomonomers or methacrylamides bearing two hydroxyethyl residues. The method and apparatus employ this coating to maintain coating integrity and suppress electroosmotic flow under basic conditions in capillary electrophoresis.

Abstract: An energy director structure with an auxiliary weld depth limitation feature is provided. The energy director is located on a first contact shelf. A second contact shelf that is shorter, broader, forming a mesa is positioned laterally adjacent to, and below, the first contact shelf. The second contact shelf forms a mesa that limits the depth of the ultrasonic welding. Limiting the time, pressure, or temperature of the welding process additionally ensures the weld depth is limited to the height of the second contact shelf or mesa. Two plastic pieces, one of which includes an energy director and mesa structure, may be welded together to form a capillary having precise volumetric accuracy.

Abstract: A method and compound for detecting low levels of microorganisms in biological samples is disclosed. In the method, an antibiotic is conjugated to a detectable label. This antibiotic/label conjugate is then introduced into a sample containing biological material. The antibiotic binds to target microorganism where the label allows for detection of localized concentrations of the antibiotic. A compound to accomplish this method is also described. This compound is an antibiotic conjugated to a fluorescent dye. This dye has an excitation and emission wavelength that are not interfered by substances typically found in biological samples.

Abstract: A bait station providing a holder for dispensing liquid bait in a refillable manner. The liquid bait is kept in a reservoir at the bottom of the bait station base. Fit into an open end of the base is an interior section comprised of two domes. The interior section fits into the base above the bait reservoir. A lid is secured over the end of the base. The dimensions of the domes are selected such that the domes contain the liquid bait if inverted and one dome contains the liquid bait held in half the reservoir. The access ports at the top of the base and between the domes provide access to the liquid bait. Refilling the station with liquid poison is effected either through a port in the lid of the bait station or by removal of the lid. Target insects enter the bait station through one or more access ports and then travel through an interior passageway to the liquid bait, which can be both an attractant and a poison.

Abstract: A sample substrate for use in a fluorescence imaging system includes a rigid base with a specularly reflective surface, typically metal, on which is deposited a transparent coating layer. The coating layer has a thickness selected so that a particular fluorescence excitation wavelength, corresponding to a specified fluorescent constituent to be sought in sample material, has an optical path from the top of the coating layer to the reflecting surface in the base of substantially an odd multiple of one-quarter wavelength, so that the standing wave of the fluorescence excitation wavelength of light incident on the substrate has an antinode located at or near where sample material would be disposed on top of the coating layer. This maximizes fluorescence excitation of the sample on the reflective substrate. The transparent coating layer may be a dielectric material (e.g. silica) or may be a multilayer structure with a top layer of biologically active material for binding a specified sample constituent.

Abstract: A liquid bait station for ants has separate nested inner and outer container sections with the inner container forming a liquid bait reservoir. The inner container section or reservoir has a lid that is closed whenever the outer container is closed, and access to the reservoir of liquid bait by the ants is indirect via one or more container access ports leading to a compartment inside the outer container and then via separate reservoir access ports leading from the compartment to the reservoir. In one embodiment, the reservoir lid comprises a raised portion in the inner surface of the outer container's own cover and the reservoir access ports are formed by depressions in that raised portion. In a second embodiment, the inner and outer container sections have separate lids, but at least one tang depending from the outer cover closes and holds down the inner lid whenever the outer cover is closed. The reservoir access ports can be holes in the inner lid.