Abstract: A method is described for distinguishing between cancerous and normal human cells. The method includes collecting cells; preparing cells for scanning; scanning of the prepared cells by means of atomic force microscopy; processing of the obtained images through specific algorithms; wherein the algorithms allowing one to identify whether the cell is cancerous or normal.

Abstract: A method for the enumeration of micronucleated erythrocyte populations while distinguishing platelet and platelet-associated aggregates involves the use of a first fluorescent labeled antibody having binding specificity for a surface marker for reticulocytes, a second fluorescent labeled antibody having binding specificity for a surface marker for platelets, and a nucleic acid staining dye that stains DNA (micronuclei) in erythrocyte populations. Because the fluorescent emission spectra of the first and second fluorescent labeled antibodies do not substantially overlap with one another or with the emission spectra of the nucleic acid staining dye, upon excitation of the labels and dye it is possible to detect the fluorescent emission and light scatter produced by the erythrocyte populations and platelets, and count the number of cells from one or more erythrocyte populations in said sample.

Abstract: The present invention relates to novel methods for detecting at least one member of a known binding pair in a sample, including a cell, where one member of the pair (termed the “receptor”) is expressed by a bacteriophage, which phage is then used to detect the presence of the other member of the pair (termed the “ligand” or “target”). Rather than detecting the binding of at least one phage using antibody-based technology, the present invention relates to detecting the nucleic acid associated with the phages. In one aspect, the invention relates to identifying at least one antigen-bearing moiety (e.g., a red blood cell antigen) of interest present on a cell, e.g., a red blood cell, using antibody-displaying bacteriophages, using antiglobulin reagent-displaying bacteriophages and detecting at least one nucleic acid associated with the phage.

Abstract: A method for the enumeration of micronucleated erythrocyte populations while distinguishing platelet and platelet-associated aggregates involves the use of a first fluorescent labeled antibody having binding specificity for a surface marker for reticulocytes, a second fluorescent labeled antibody having binding specificity for a surface marker for platelets, and a nucleic acid staining dye that stains DNA (micronuclei) in erythrocyte populations. Because the fluorescent emission spectra of the first and second fluorescent labeled antibodies do not substantially overlap with one another or with the emission spectra of the nucleic acid staining dye, upon excitation of the labels and dye it is possible to detect the fluorescent emission and light scatter produced by the erythrocyte populations and platelets, and count the number of cells from one or more erythrocyte populations in said sample.

Abstract: The present invention relates to novel methods for detecting a member of a known binding pair in a sample, including a cell, where one member of the pair (termed the “receptor”) is expressed by a bacteriophage, which phage is then used to detect the presence of the other member of the pair (termed the “ligand” or “target”). Rather than detecting the binding of the phage using antibody-based technology, the present invention relates to detecting the nucleic acid associated with the phage. In one aspect, the invention relates to identifying an antigen-bearing moiety (e.g., a red blood cell antigen) of interest present on a cell, e.g., a red blood cell, using antibody-displaying bacteriophage, as well as detecting anti-red blood cell auto- or alloantibodies and/or complement in a sample, using antiglobulin reagent-displaying bacteriophage and detecting a nucleic acid associated with the phage.

Abstract: The invention relates to a method for detecting a plurality of antigenic molecules carried by erythrocytes and/or a plurality of anti-erythrocyte antibodies of an individual, comprising bringing a sample into contact with distinguishable beads, on which are attached a) antibodies specific for said antigens, or b) erythrocytes, erythrocyte membrane fragments or blood group antigens.

Abstract: The invention relates to a method for detecting a plurality of antigenic molecules carried by erythrocytes and/or a plurality of anti-erythrocyte antibodies, said antigenic molecules carried by the erythrocytes consisting of antigenic molecules carried not only by the erythrocytes, but also by at least one other cell population, other than the blood group antigen molecules, said method comprising bringing a sample into contact with distinguishable beads, on which are attached a) antibodies specific for said antigens, or b) erythrocytes or erythrocyte membrane fragment.

Abstract: The present disclosure relates to novel bis-maleic anhydrides and to the surprising discovery that bis-maleic anhydride cross-linking agents can be used for preservation/fixation of a cell or tissue sample. Various bis-maleic anhydride cross-linking agent scan be used in methods requiring fixation of a cell or tissue sample. These reagents and methods are especially useful in procedures that require that the fixation agent be removed in order to facilitate analysis with other reagents. The inventive reagents and methods make it easier to reliably assay for various proteins, a nucleic acid and the like using analytical methods such as like immunohistochemistry, fluorescence in situ hybridization, RT-PCR, and the like.

Abstract: The invention relates to methods and kits for the quantitative analysis of in vivo mutation frequencies of the Pig-A gene in individuals exposed to a genotoxicant, particularly using peripheral blood samples of vertebrates.

Abstract: A method for the enumeration of micronucleated erythrocyte populations while distinguishing platelet and platelet-associated aggregates involves the use of a first fluorescent labeled antibody having binding specificity for a surface marker for reticulocytes, a second fluorescent labeled antibody having binding specificity for a surface marker for platelets, and a nucleic acid staining dye that stains DNA (micronuclei) in erythrocyte populations. Because the fluorescent emission spectra of the first and second fluorescent labeled antibodies do not substantially overlap with one another or with the emission spectra of the nucleic acid staining dye, upon excitation of the labels and dye it is possible to detect the fluorescent emission and light scatter produced by the erythrocyte populations and platelets, and count the number of cells from one or more erythrocyte populations in said sample.

Abstract: The present invention relates a method for the enumeration of in vivo gene mutation. The method utilizes differential staining of GPI-anchor deficient erythrocyte populations to distinguish between wild-type and pig-a gene mutants. Quantitative analyses can be conducted on erythrocytes and/or reticulocytes, and is based upon fluorescent emission and light scatter following exposure to an excitatory light source. Counting of mutant erythrocytes or reticulocytes relative to the number of total erythrocytes or reticulocytes can be used to assess the DNA-damaging potential of an exogenous chemical agent, the DNA-damaging potential of an exogenous physical agent, the effects of an exogenous agent which can modify endogenously-induced DNA damage, and the effects of an exogenous agent which can modify exogenously-induced DNA damage. Kits for practicing the invention are also disclosed.

Abstract: An assay stick 7 includes a transparent reaction vessel or tube 14 having one or more microbeads 8 disposed therein. The microbeads 8 have a plurality of unique identification digital codes based on a diffraction grating 12 disposed therein that are detected when illuminated by incident light 24. The incident light 24 may be directed transversely onto the side or onto an end of the tube 14 with a narrow band (single wavelength) or multiple wavelength source, in which case the code is represented by a spatial distribution of light or a wavelength spectrum, respectively. The assay stick 7 may be reused or disposed upon completion of the assay. Alternatively, the beads may be attached to a strip or planar surface. The encoded beads can also provide traceability, quality-control, and authenticity of each bead 8 to its source and/or to the chemistry on each bead 8. Also, the low sample volume of the assay stick allows for faster reactions and better sensitivity.

Abstract: Disclosed are methods for detecting antibody in a sample, where the antibody targets an antigen expressed by red blood cells or red blood cell ghosts. Rather than detecting the binding events between a particular antigen antibody pair (as in traditional agglutination based assays) the methods herein allow for multiplexed detection of clinically important allo-immune antibodies to blood group antigens. Specifically the method involves generating fluorescently encoded red blood cells or red blood cell ghosts with known antigen presentation and using them to detect the presence of antibody in serum/plasma with a fluorescent sandwich type immunoassay. The assay results can be read using flow cytometric or fluorescent microscope based imaging techniques.

Abstract: A method for the enumeration of micronucleated erythrocyte populations while distinguishing platelet and platelet-associated aggregates involves the use of a first fluorescent labeled antibody having binding specificity for a surface marker for reticulocytes, a second fluorescent labeled antibody having binding specificity for a surface marker for platelets, and a nucleic acid staining dye that stains DNA (micronuclei) in erythrocyte populations. Because the fluorescent emission spectra of the first and second fluorescent labeled antibodies do not substantially overlap with one another or with the emission spectra of the nucleic acid staining dye, upon excitation of the labels and dye it is possible to detect the fluorescent emission and light scatter produced by the erythrocyte populations and platelets, and count the number of cells from one or more erythrocyte populations in said sample.

Abstract: The present invention relates a method for the enumeration of in vivo gene mutation. The method utilizes differential staining of GPI-anchor deficient erythrocyte populations to distinguish between wild-type and pig-a gene mutants. Quantitative analyses can be conducted on erythrocytes and/or reticulocytes, and is based upon fluorescent emission and light scatter following exposure to an excitatory light source. Counting of mutant erythrocytes or reticulcoytes relative to the number of total erythrocytes or reticulocytes can be used to assess the DNA-damaging potential of an exogenous chemical agent, the DNA-damaging potential of an exogenous physical agent, the effects of an exogenous agent which can modify endogenously-induced DNA damage, and the effects of an exogenous agent which can modify exogenously-induced DNA damage. Kits for practicing the invention are also disclosed.

Abstract: This invention is directed to a method for preparation of a biological sample for measurement of protein epitopes that allows for the preservation of intracellular protein epitopes and detection of signal transduction pathways based on the ability to capture transient activation states of the epitopes. The method provided by the invention allows for the rapid fixation of biological samples containing red blood cells, to ensure that epitopes of signal transduction molecules and other intracellular protein epitopes are preserved in the active state. The method of the invention further allows for lysis of red blood cells, thereby making it a useful method for cytometric analysis of biological samples, including, for example, whole blood, bone marrow aspirates, peritoneal fluids, and other red blood cell containing samples. The invention also provides a method to recover or “unmask” epitopes on intracellular antigens that have been made inaccessible by the cross linking fixative necessary to fix the sample.

Abstract: The invention provides for a process for preparing a sensitivity control for blood group determination including dissolving an amount of an antigen in water to give an antigen solution of known concentration, contacting the antigen solution with cells to allow insertion of antigen molecules into the cell membranes of the cells to give transformed cells or contacting the antigen solution with cells that have been modified by the insertion of a linker molecule into the membranes of the cells to allow attachment of antigen molecules to the linker molecules to give transformed cells, washing the transformed cells to give a transformed cell solution, and determining the concentration of the transformed cell solution to enable the solution to be used as a sensitivity control for blood group determination.

Abstract: The present invention describes semi- and fully-automated methods and reagents therefor for the assay and analysis of body fluid samples, particularly non-blood samples. The methods and reagents are especially useful for the assay and analysis of cerebrospinal fluid (CSF) samples. The reagent compositions sphere and fix all cells in the sample in suspension. Reported results can include red blood cell (RBC) and white blood cell (WBC) counts, WBC differential values, cell-by-cell volumes and dry-mass concentrations.

Abstract: An automated in situ heat induced antigen recovery and staining method and apparatus for treating a plurality of microscope slides. The process of heat induced antigen recovery and the process of staining the biological sample on the microscope slide are conducted in the same apparatus, wherein the microscope slides do not need to be physically removed from one apparatus to another. Each treatment step occurs within the same reaction compartment. The reaction conditions of each reaction compartment for treating a slide can preferably be controlled independently, including the individualized application of reagents to each slide and the individualized treatment of each slide. The reagents are preferably held in a reagent dispensing strip similar to a “blister pack”.

Abstract: It is an object of the present invention to provide magnetic substance-encapsulated particles which have uniform magnetism, high dispersion stability and a narrow particle size distribution, a method of producing the same, particles for immunoassay formed by using the magnetic substance-encapsulated particles and a method of immunoassay in which the magnetic substance-encapsulated particles or the particles for immunoassay are used. The present invention relates to a magnetic substance-encapsulated particle, which comprises an organic polymer material and a magnetic substance having an average particle size of 1 to 30 nm, the magnetic substance being contained within a particle in a state of being dispersed.

Abstract: An automated in situ heat induced antigen recovery and staining method and apparatus for treating a plurality of microscope slides. The process of heat induced antigen recovery and the process of staining the biological sample on the microscope slide are conducted in the same apparatus, wherein the microscope slides do not need to be physically removed from one apparatus to another. Each treatment step occurs within the same reaction compartment. The reaction conditions of each reaction compartment for treating a slide can preferably be controlled independently, including the individualized application of reagents to each slide and the individualized treatment of each slide. The reagents are preferably held in a reagent dispensing strip similar to a “blister pack”.

Abstract: Disclosed are methods for detecting antibody in a sample, where the antibody targets an antigen expressed by red blood cells or red blood cell ghosts. Rather than detecting the binding events between a particular antigen antibody pair (as in traditional agglutination based assays) the methods herein allow for multiplexed detection of clinically important allo-immune antibodies to blood group antigens. Specifically the method involves generating fluorescently encoded red blood cells or red blood cell ghosts with known antigen presentation and using them to detect the presence of antibody in serum/plasma with a fluorescent sandwich type immunoassay. The assay results can be read using flow cytometric or fluorescent microscope based imaging techniques.

Abstract: This invention relates to the field of biological assays where cells can be classified and enumerated using flow cytometry optical instrumentation. The invention combines information from multi-angle, light scatter from the cell itself and multi-angle light scatter from small, optically resonant particles that are selectively bound to surface molecules on the cell to carry out classification and enumeration. This light scatter method enables an instrumentation system that is simple to use, inexpensive to build, and mechanically robust; making it suitable for use in remote clinical environments.

Abstract: The invention is a method for analyzing immature reticulocytes for the presence of micronuclei. The method includes reticulocyte enrichment, fluorescent labeling, micronuclei staining, and analysis using single-laser flow cytometry. The invention also includes kits containing reagents to use in the method.

Abstract: A method for the enumeration of micronucleated erythrocyte populations while distinguishing platelet and platelet-associated aggregates involves the use of a first fluorescent labeled antibody having binding specificity for a surface marker for reticulocytes, a second fluorescent labeled antibody having binding specificity for a surface marker for platelets, and a nucleic acid staining dye that stains DNA (micronuclei) in erythrocyte populations. Because the fluorescent emission spectra of the first and second fluorescent labeled antibodies do not substantially overlap with one another or with the emission spectra of the nucleic acid staining dye, upon excitation of the labels and dye it is possible to detect the fluorescent emission and light scatter produced by the erythrocyte populations and platelets, and count the number of cells from one or more erythrocyte populations in said sample.

Abstract: A method and apparatus are provided for aligning optical elements or microbeads, wherein each microbead has an elongated body with a code embedded therein along a longitudinal axis thereof to be read by a code reading device. The microbeads are aligned with a positioning device so the longitudinal axis of the microbeads is positioned in a fixed orientation relative to the code reading device. The microbeads are typically cylindrically shaped glass beads between 25 and 250 microns (?m) in diameter and between 100 and 500 ?m long, and have a holographic code embedded in the central region of the bead, which is used to identify it from the rest of the beads in a batch of beads with many different chemical probes. A cross reference is used to determine which probe is attached to which bead, thus allowing the researcher to correlate the chemical content on each bead with the measured fluorescence signal.

Abstract: A method and apparatus for preparing biological cell samples for intracellular analysis. The invention is based upon the recognition that many of the steps of the conventional methods for such sample preparation can be eliminated, leading to a process that readily lends itself to automation and the advantages associated therewith. The method of the invention comprises the steps of (a) cell-fixation, (b) permeabilization and (c) staining (or labeling) of intracellular molecules of interest by probes that are readily detectable by flow cytometric techniques, all without any intervening cell-washing (and re-suspension) steps. Rather, the single cell-washing step is effected after these three steps have been carried out. Preferably, the washing step is carried out by passing the fixed, permeabilized and stained cell sample through a semi-permeable membrane that serves to filter out (by transmission) interferants to waste while retaining the cells of interest.

Abstract: This invention relates to clinical diagnostic assays, related optical bio-discs, and a disc-reading apparatus. The invention is directed to methods and apparatuses for performing immunohematology assays using an optical bio-disc analysis system. The invention is further directed to an optical bio-disc for performing an immunohematologic assay including a substrate having encoded information associated therewith. The encoded information may be readable by a disc drive assembly to control rotation of the disc. The disc may also include at least one target zone or capture zone associated with the substrate. The target zone is disposed at a predetermined location relative to a center of the substrate. The disc further includes a plurality of capture antibodies immobilized within the target zone, a flow channel, fluidic circuit, or analysis chamber associated with the target zone, and an input site in fluid communication with the analysis chamber.

Abstract: A chromatography assay device and method for use with whole blood samples utilizing a red blood cell separating agent to aggregate red blood cells and permit plasma or serum to flow by capillary action and a neutralizing agent to neutralize any effects the red blood cell separating agent may have on the device and method.

Abstract: An automated in situ heat induced antigen recovery and staining method and apparatus for treating a plurality of microscope slides. The process of heat induced antigen recovery and the process of staining the biological sample on the microscope slide are conducted in the same apparatus, wherein the microscope slides do not need to by physically removed from one apparatus to another. Each treatment step occurs within the same reaction compartment. The reaction conditions of each reaction compartment for treating a slide can preferably be controlled independently, including the individualized application of reagents to each slide and the individualized treatment of each slide. The reagents are preferably held in a reagent dispensing strip similar to a “blister pack”.

Abstract: A process for permeabilizing erythrocytes in which the erythrocytes are subjected successively to the action of (a) a fixing agent containing an aliphatic aldehyde and oligosaccharide, (b) a permeabilizing agent containing a detergent and an oligosaccharide, kit for permeabilizing erythrocytes, kit for immuno-marking fetal erythrocytes, and a process for identifying fetal erythrocytes by immuno-marking.

Abstract: Method and test kit for assaying in a sample an analyte which is a bloodgroup antigen present on erythrocytes or an antibody binding to such a bloodgroup antigen. To that end, the sample is treated with a reagent containing a binding partner for the analyte, so that a complex of bloodgroup antigen present on erythrocytes and antibody bound thereto is formed if the sample contains analyte. The analyte is a bloodgroup antigen present on erythrocytes, the analyte binding partner is an antibody capable of binding to the bloodgroup antigen and if the analyte is an antibody binding to a bloodgroup antigen, the analyte binding partner is the bloodgroup antigen present on erythrocytes. Erythrocytes, complex or non-complexed, are then separated from non-bound antibodies using a separation medium with a density higher than that of the liquid containing the antibodies but lower than the density of crythrocytes.

Abstract: A single laser flow cytometric method for the enumeration of micronuclei in erythrocyte populations, wherein a sample of peripheral blood or bone marrow is obtained and the cell populations in the sample are fixed. Reticulocytes in the fixed samples are treated simultaneously with RNAse and with a fluorescent labeled antibody having binding specificity for a surface marker for erythroblasts/reticulocytes. The erythrocyte populations are then stained with a nucleic acid stain which stains DNA representing micronuclei, if present. The stained and/or labeled erythrocyte populations are then exposed to a laser beam of appropriate excitation wavelength for both the nucleic acid staining dye and the fluorescent label to produce fluorescent emission. The fluorescent emission and light scatter produced by the erythrocyte populations are detected by the flow cytometer from which is calculated the number of specific erythrocyte populations in said sample.

Abstract: The invention relates to methods of agglutinating or capturing cells comprising providing a mixture comprising a population of cells and a population of bacteriophage expressing a first antibody on the surface of the bacteriophage, the first antibody being specific for an antigen-bearing moiety expressed by at least a portion of the cells in the cell population, wherein the first antibody binds to the portion of the cells causing the bacteriophage to also bind to the portion of the cells, adding to the mixture a second antibody specific for the bacteriophage, wherein binding of the second antibody to bacteriophage bound to the portion of the cells causes the portion of the cells to agglutinate or be captured.

Abstract: A first embodiment comprises reacting PSI with polyhydrazide selected from the group consisting of dihydrazides and trihydrazides and mixtures thereof, subsequently hydrolyzing the crosslinked PSI with base to produce crosslinked polyaspartate. A second embodiment comprises reacting PSI with hydrazine to form an intermediate product which is reacted with polyacyl chloride or polyester to produce crosslinked PSI followed by hydrolysis to form crosslinked salt. Isolation of the intermediate before reaction with the polyacyl chloride or polyester is unnecessary.

Abstract: The invention provides compounds which specifically inhibit factor Xa activity. The compounds consist of the structure X.sub.1 -YIR-X.sub.2, wherein X.sub.1 is H, acyl, alkyl, acylalkyl, arylalkyl or one or more amino acids, and X.sub.2 is a modified C-terminal group, one or more carboxy-protecting groups or one or more amino acids or other substituent, and Y, I and R are tyrosine, isoleucine and arginine, respectively, or peptidomimetic or organic structures that possess the same functional activity as Y, I and R, respectively. In addition, the present invention provides a compound having the structure A1-A2-(A3).sub.m --B, where m is 0 or 1. A compound of the invention can be linear or cyclic and can be about 2 and 43 residues in length. A compound of the invention is characterized, in part, in that it exhibits a specific inhibition of factor Xa activity with a K.sub.i of .ltoreq.100 .mu.M, preferably .ltoreq.

Abstract: Immunoassays of psychoactive drugs including psychotomimetic drugs, narcotic drugs, and tetrahydrocannabinols and treatment methods based on the antigenic properties of protein conjugates of these drugs. These methods are based upon treating the psychoactive substances as haptens and utilizing their protein conjugates to produce antibodies to the psychoactive materials themselves. The immunoassay methods include both agglutination and agglutination-inhibition reactions. The treatment methods include treatment or both exogenous, administered drugs (such as cannabinols, LSD, heroin and morphine) and endogenous substances (such as N,N-Dimethyltryptamine and 5-Methoxy-N,N-Dimethyltryptamine, by active immunization and also passive immunization.

Abstract: HIV-1 peptides having at least one point mutation between position 593 and 611 of the HIV-1 gp160 amino acid sequence. The point mutation either is at position 604 or 610, or both positions. Immunoassays which utilize these peptides are provided, as well as, diagnostic test kits which contain these peptides.

Abstract: A solid phase method of detection or assay of the presence or amount in a serum or plasma sample of a target antibody specific to a cell surface antigen. The sample is contacted with an immobilised preparation of cells bearing the antigen and antibody bound thereto is detected or assayed by means of an indicator comprising a binding partner for the antibody bound to labelled latex particles.

Abstract: Immunoassays of psychoactive drugs including psychotomimetic drugs, narcotic drugs, and tetrahydrocannabinols and treatment methods based on the antigenic properties of protein conjugates of these drugs. These methods are based upon treating the psychoactive substances as haptens and utilizing their protein conjugates to produce antibodies to the psychoactive materials themselves. The immunoassay methods include both agglutination and agglutination-inhibition reactions. The treatment methods include treatment of both exogenous, administered drugs (such as cannabinols, LSD, heroin and morphine) and endogenous substances (such as N,N-Dimethyltryptamine and 5-Methoxy-N,N-Dimethyltryptamine), by active immunization and also passive immunization.

Abstract: Analytical reagents designated "release tags", for labeling molecular species with a highly detectable signal group which can be released in the form of a volatile compound at a desired point in an analytical procedure. In one embodiment, the release tags have the formula(SgCo).sub.x L(Rx).sub.rwherein each Sg is a signal group bearing one or more electronegative substituents, L is any of a wide variety of groups which when attached to a carbonyl group form a readily cleaved linkage, each COL moiety is a release group which upon scission releases signal group Sg in the form of a volative compound, and each Rx is a reactivity group for attaching the release tag compound to a molecular species to be labeled. In a second embodiment, the release tags have the formulaSgReRxwherein Sg and Rx are defined as above and Re is a release group which is an olefin, .alpha.-hydroxy ketone or vicinal diol. Conjugates of the release tag compounds and assay methods employing them are also disclosed.

Abstract: Immunoassays of psychoactive drugs including psychotomimetic drugs, narcotic drugs, and tetrahydrocannabinols and treatment methods based on the antigenic properties of protein conjugates of these drugs. These methods are based upon treating the psychoactive substances as haptens and utilizing their protein conjugates to produce antibodies to the psychoactive materials themselves. The immunoassay methods include both agglutination and agglutination-inhibition reactions. The treatment methods include treatment or both exogenous, administered drugs (such as cannabinols, LSD, heroin and morphine) and endogenous substances (such as N,N-Dimethyltryptamine and 5-Methoxy-N,N-Dimethyltryptamine by active immunization and also passive immunization.

Abstract: A method is provided for the preparation of semisolid particles or cells that have been chemically derivatized resulting in hydrazide functionalities covalently incorporated onto cell surface membrane molecules of the semisolid particles or cells, as well as a method for determining the levels of hydrazide groups on the particles or cells. The method involves the preparation and analysis of red blood cells chemically derivatized in such a manner that hydrazide functionalities have been covalently incorporated onto the cell membrane molecules, the preparation of hydrazine derivatized cells and the use thereof of the novel cells in agglutination reactions to promote the attachment of antigens and antibodies to the hydrazine derivatized cells without loss of antibody activity or the blocking of the etitope of interest.

Abstract: HIV-1 peptides having at least one point mutation between position 593 and 611 of the HIV-1 gp160 amino acid sequence. The point mutation either is at position 604 or 610, or both positions. Immunoassays which utilize these peptides are provided, as well as, diagnostic test kits which contain these peptides.

Abstract: A process for preparing a purified syphilis antigen which comprises adsorbing an extract originated from Treponemda pallidum on a hydroxyapatite gel, followed by elution, while an aqueous medium is used.

Abstract: A hematology control product comprising leukocyte analogs and an aqueous solution of a plasma substance for use in a blood counting instrument is described. The instrument employs a lytic reagent system for the lysable red blood cells in the control product. The plasma substance is in an amount effective to enable the differentiation of each of said leukocyte analogs relative to the physical attributes of the analogs, said physical attributes of the analog are similar to human leukocytes. Preferably, the plasma substance comprises cholesterol or its derivatives.A method for using the cell suspension media comprising an aqueous solution of a plasma substance is also described. The method provides a quality control to determine whether an instrument is operating within manufacturer's specifications.

Abstract: A method for detecting the presence of a specific analyte in solution comprising the steps of affixing to a chromatographic medium a first antibody which binds with specificity to the analyte in a pattern which forms a pre-determined geometric symbol or symbols consisting of a plurality of line segments; partially blocking or obstructing the expected passage of a moving phase or solvent through the symbol; reacting the solution to a marker-second antibody complex which binds with specificity to the analyte to form analyte-marker-second antibody complexes in the presence of the analyte; eluting the solution containing any analyte-marker-second antibody complex through the partially blocked or obstructed medium; and observing the substantially complete formation, or lack thereof, of the predetermined geometric symbol or symbols by means of the marker.

Abstract: The invention relates to a method of preparing a reagent for the determination by hemagglutination of antibodies to bacterial toxins. According to this method erythrocytes are treated with glutaraldehyde and then with the bacterial toxins in the presence of glutaraldehyde without a wash step. The reagent thus obtained is further treated with a reagent for blocking aldehyde groups.

Abstract: A method for preparation in a large quantity of human serum albumin-sensitized sheep erythrocytes is described. The sensitized cells are useful for detecting Hepatitis B virus pre-S.sub.2 antigen. The method uses human serum albumin sensitized glutaraldehyde-fixed, sheep erythrocytes in the presence of chromium chloride.

Abstract: A method for drying mammalian cells, such as erythrocytes, lymphocytes, leukocytes and platelets onto a solid-phase support for use in solid-phase immunoassays through use of a drying solution and an article for use in immunoassays prepared by such method. The method comprises immobilizing a monolayer of cells onto the solid-phase support by non-covalent binding. This is accomplished by staining the solid-phase support with an organic dye having a net positive charge which permits non-covalent binding of the cells which carry a net negative charge to the solid-phase support. These cells are dried or fixed to the solid-phase support by addition of a drying solution which comprises an aqueous solution of a monosaccharide, disaccharide, trisaccharide or cyclitol and a salt. The preferred monosaccharide is D-(-)glucose and the preferred salt is sodium chloride. The preferred drying solution comprises a 1.0 M solution of dextrose and a 154 mM solution of sodium chloride.