1595 results about "Flow cytometry" patented technology

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.

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.

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.