1616 results about "Flow cytometry" patented technology

Peripheral blood leucocytes incubated with a semi-synthetic phage antibody library and fluorochrome-labeled CD3 and CD20 antibodies were used to isolate human single chain Fv antibodies specific for subsets of blood leucocytes by flow cytometry. Isolated phage antibodies showed exclusive binding to the subpopulation used for selection or displayed additional binding to a restricted population of other cells in the mixture. At least two phage antibodies appeared to display hithereto unknown staining patterns of B lineage cells. This approach provides a subtractive procedure to rapidly obtain human antibodies against known and novel surface antigens in their native configuration, expressed on phenotypically defined subpopulations of cells. Importantly, this approach does not depend on immunization procedures or the necessity to repeatedly construct phage antibody libraries.

A method for the analysis of DNA sequences and PCR products comprises the steps of constructing an oligonucleotide-labeled beadset, and labeled complementary probe, and exposing the beadset and probe to a DNA fragment or PCR product under hybridizing conditions and analyzing the combined sample / beadset by flow cytometry. Flow cytometric measurements are used to classify beads within an exposed beadset to determine the presence of identical or nonidentical sequences within the test sample. The inventive technology enables the rapid analysis of DNA sequences and detection of point mutations, deletions and / or inversions while also reducing the cost and time for performing genetic assays.

A method for the multiplexed diagnostic and genetic analysis of enzymes, DNA fragments, antibodies, and other biomolecules comprises the steps of constructing an appropriately labeled beadset, exposing the beadset to a clinical sample, and analyzing the combined sample / beadset by flow cytometry. Flow cytometric measurements are used to classify, in real-time, beads within an exposed beadset and textual explanations, based on the accumulated data obtained during real-time analysis, are generated for the user. The inventive technology enables the simultaneous, and automated, detection and interpretation of multiple biomolecules or DNA sequences in real-time while also reducing the cost of performing diagnostic and genetic assays.

Many areas of biomedical research depend on the analysis of uncommon variations in individual genes or transcripts. Here we describe a method that can quantify such variation at a scale and ease heretofore unattainable. Each DNA molecule in a collection of such molecules is converted into a single particle to which thousands of copies of DNA identical in sequence to the original are bound. This population of beads then corresponds to a one-to-one representation of the starting DNA molecules. Variation within the original population of DNA molecules can then be simply assessed by counting fluorescently-labeled particles via flow cytometry. Millions of individual DNA molecules can be assessed in this fashion with standard laboratory equipment. Moreover, specific variants can be isolated by flow sorting and employed for further experimentation. This approach can be used for the identification and quantification of rare mutations as well as to study variations in gene sequences or transcripts in specific populations or tissues.

The enumeration of cells in fluids by flow cytometry is widely used across many disciplines such as assessment of leukocyte subsets in different bodily fluids or of bacterial contamination in environmental samples, food products and bodily fluids. For many applications the cost, size and complexity of the instruments prevents wider use, for example, CD4 analysis in HIV monitoring in resource-poor countries. The novel device, methods and algorithms disclosed herein largely overcome these limitations. Briefly, all cells in a biological sample are fluorescently labeled, but only the target cells are also magnetically labeled. The labeled sample, in a chamber or cuvet, is placed between two wedge-shaped magnets to selectively move the magnetically labeled cells to the observation surface of the cuvet. An LED illuminates the cells and a CCD camera captures the images of the fluorescent light emitted by the target cells. Image analysis performed with a novel algorithm provides a count of the cells on the surface that can be related to the target cell concentration of the original sample. The compact cytometer system provides a rugged, affordable and easy-to-use technique, which can be used in remote locations.

The methods and reagents described in this invention are used to analyze circulating tumor cells, clusters, fragments, and debris. Analysis is performed with a number of platforms, including flow cytometry and the CellSpotter® fluorescent microscopy imaging system. Analyzing damaged cells has shown to be important. However, there are two sources of damage: in vivo and in vitro. Damage in vivo occurs by apoptosis, necrosis, or immune response. Damage in vitro occurs during sample acquisition, handling, transport, processing, or analysis. It is therefore desirable to confine, reduce, eliminate, or at least qualify in vitro damage to prevent it from interfering in analysis. Described herein are methods to diagnose, monitor, and screen disease based on circulating rare cells, including malignancy as determined by CTC, clusters, fragments, and debris. Also provided are kits for assaying biological specimens using these methods.

This invention is related to a flow fluorometric device and method employing a two-photon excitation and / or confocal optical set-up. The optical set-up of this invention is optimal for counting small fluorescent biological particles. The active focal volume is diffraction-limited and consequently much smaller than the volume of the flow channel. The excitation and detection concept has been found very efficient for rejection of the background signal. An objective lens with large numerical aperture for focusing the laser and for collecting the fluorescence is used and this restricts the active volume of measurement to a diffraction-limited volume which approximately corresponds to a volume of femtoliter. This volume is significantly smaller than the detection volume of ordinary flow cytometry.

A method for the assay of N samples each containing a compound to be tested, comprises providing N reaction vessels each containing a population of carrier beads and other reagents for performing the assay, where N is at least 2 e.g. 80-4000. Each population of carrier beads is distinguishable from every other population. After adding the samples to the reaction vessels and performing the assays, the contents of all the reaction vessels are mixed and subjected to analysis by flow cytometry. By means of flow cytometry, each carrier bead is rapidly analysed to identify its population and also to determine the presence or concentration or biological activity of the compound to be tested.

DNA polymorphism identity determination using flow cytometry. Primers designed to be immobilized on microspheres are allowed to anneal to the DNA strand under investigation, and are extended by either DNA polymerase using fluorescent dideoxynucleotides or ligated by DNA ligase to fluorescent reporter oligonucleotides. The fluorescence of either the dideoxynucleotide or the reporter oligonucleotide attached to the immobilized primer is measured by flow cytometry, thereby identifying the nucleotide polymorphism on the DNA strand.

SNAIL provides cost-efficient detection of specific nucleic acids in single cells, and may be combined with flow cytometry to simultaneously analyze large numbers of cells for a plurality of nucleic acids, e.g. at least one, to up to 5, up to 10, up to 15, up to 20 or more transcripts can be simultaneously analyzed, at a rate of up to about 50, 100, 250, 500 or more cells / second. The methods require only two primers for amplification, and may further include a detection primer.

The present invention provides a method of cryopreserving sperm that have been selected for a specific characteristic. In a preferred embodiment, the method is employed to freeze sex-selected sperm. Although the cryopreservation method of the invention can be used to freeze sperm selected by any number of selection methods, selection using flow cytometry is preferred. The present invention also provides a frozen sperm sample that has been selected for a particular characteristic, such as sex-type. In preferred embodiments, the frozen sperm sample includes mammalian sperm, such as, for example, human, bovine, equine, porcine, ovine, elk, or bison sperm. The frozen selected sperm sample can be used in a variety of applications. In particular, the sample can be thawed and used for fertilization. Accordingly, the invention also includes a method of using the frozen selected sperm sample for artificial insemination or in vitro fertilization.

The present invention provides instruments for analyzing a multiplicity of fluorescent dyes using a multiplicity of amplifying photodetectors, methods for using the instruments, methods for setting the instrument parameters, and methods for resetting the instrument parameters following a changed in photodetector amplification. The present invention is particularly applicable in the field of flow cytometry.

It is intended to provide a method whereby a plural number of antibodies against cell surface antigens are quickly classified and to provide a method whereby antigens of the thus classified antibodies are quickly identified. Further, it is intended to provide a method of promoting the utilization of the useful data obtained by the above methods. Furthermore, it is intended to provide an antibody which is effective in treating or diagnosing cancer. Namely, a method of classifying antibodies which comprises: (1) the step of preparing a plural number of antibodies respectively recognizing cell surface antigens; (2) the step of bringing each of these antibodies into contact with a cell of the same species; (3) the step of analyzing each of the cells having been treated in the step (2) by flow cytometry and thus obtaining data indicating the reactivity of each antibody with its cell surface antigen; and (4) the step of comparing the thus obtained data and classifying the individual antibodies depending on the similarity. A method of identifying antigens which further comprises: (5) the step of selecting one to several antibodies from each antibody group formed in the step (4) and identifying antigens thereof; and (6) on the assumption that antigens of the antibodies belonging to a single antibody group are the same or highly related to one another, making relations between the antigens having been identified in the step (5) and the antibody groups to thereby identify the antigens. An antibody against HER1, an antibody against HER2, an antibody against CD46, an antibody against ITGA3, an antibody against ICAM1, an antibody against ALCAM, an antibody against CD147, an antibody against C1qR, an antibody against CD44, an antibody against CD73, an antibody against EpCAM and an antibody against HGFR, each obtained by using the above methods.

Specificity in immune responses is in part controlled by the selective interaction of T cell receptors with their cognate ligands, peptide / MHC molecules. The discriminating nature of this interaction makes these molecules, in soluble form, good candidates for selectively regulating immune responses. Attempts to exploit soluble analogs of these proteins has been hampered by the intrinsic low avidity of these molecules for their ligands. To increase the avidity of soluble analogs for their cognates to biologically relevant levels, divalent peptide / MHC complexes or T cell receptors (superdimers) were constructed. Using a recombinant DNA strategy, DNA encoding either the MHC class II / peptide or TCR heterodimers was ligated to DNA coding for murine Ig heavy and light chains. These constructs were subsequently expressed in a baculovirus expression system. Enzyme-linked immunosorbant assays (ELISA) specific for the Ig and polymorphic determinants of either the TCR or MHC fraction of the molecule indicated that infected insect cells secreted approximately 1 .mu.g / ml of soluble, conformnationally intact chimeric superdimers. SDS PAGE gel analysis of purified protein showed that expected molecular weight species. The results of flow cytometry demonstrated that the TCR and class II chimeras bound specifically with high avidity to cells bearing their cognate receptors. These superdimers will be useful for studying TCR / MHC interactions, lymphocyte tracking, identifying new antigens, and have possible uses as specific regulators of immune responses.

The invention provides methods and compositions for simultaneously detecting the activation state of a plurality of proteins in single cells using flow cytometry. The invention further provides methods and compositions of screening for bioactive agents capable of coordinately modulating the activity of a plurality of proteins in single cells. The methods and compositions can be used to determine the protein activation profile of a cell for predicting or diagnosing a disease state, and for monitoring treatment of a disease state.

The present invention provides methods and compositions for isolating and detecting rare cells from a biological sample containing other types of cells. In particular, the present invention includes a debulking step that uses a microfabricated filters for filtering fluid samples and the enriched rare cells can be used in a downstream process such as identifies, characterizes or even grown in culture or used in other ways. The invention also include a method of determining the aggressiveness of the tumor or of the number or proportion of cancer cells in the enriched sample by detecting the presence or amount of telomerase activity or telomerase nucleic acid or telomerase expression after enrichment of rare cells. This invention further provides an efficient and rapid method to specifically remove red blood cells as well as white blood cells from a biological sample containing at least one of each of red blood cells and white blood cells, resulting in the enrichment of rare target cells including circulating tumor cells (CTC), stromal cells, mesenchymal cells, endothelial cells, fetal cells, stem cells, non-hematopoietic cells etc from a blood sample. The method is based upon combination of immuno-microparticles (antibody coated microparticles) and density-based separation. The final enriched target cells can be subjected to a variety of analysis and manipulations, such as flowcytometry, PCR, immunofluorescence, immunocytochemistry, image analysis, enzymatic assays, gene expression profiling analysis, efficacy tests of therapeutics, culturing of enriched rare cells, and therapeutic use of enriched rare cells. In addition, depleted plasma protein and white blood cells can be optionally recovered, and subjected to other analysis such as inflammation studies, gene expression profiling, etc.

An apparatus (100) for sequentially analyzing particles such as single cells or single beads, by spectrometry. The apparatus, an elemental flow cytometer, includes means (102) for sequential particle introduction, means (104) to vaporize, atomize and excite or ionize the particles, or an elemental tag associated with an analyte on the particles, and means (106) to analyze the elemental composition of the vaporized, atomized and excited or ionized particles, or an elemental tag associated with the particles. Methods for sequentially analyzing particles such as singe cells or single beads by spectrometry are also described.