403 results about "False-positive result" patented technology

The present invention provides nucleic acid amplification methods that desirably reduce or eliminate false positive amplification signals resulting from contaminating biological material, e.g., nucleic acid, that may be present in one or more reagents used in an amplification reaction and / or that may be present in the environment in which an amplification reaction is performed. The invention offers the further advantage of requiring less stringent purification and / or sterility efforts than conventionally needed in order to ensure that enzymes and other reagents used in amplification reactions, and the environment in which an amplification reaction is performed, are free of bacterial or other nucleic acid contamination that may yield false positive results.

The invention discloses a circulating tumor cell identification kit and a circulating tumor cell identification method. The circulating tumor cell identification kit comprises a detection probe for detecting mRNA of an epithelial cell marking gene and / or mRNA of a mesenchymal cell marking gene, wherein the epithelial cell marking gene is selected from one or more of CDH2, VIMENTIN, FN1 and AKT2. Multiple RNA probes are adopted in the identification method, specific genes of a plurality of circulating tumor cells (CTCs) can be marked at the same time and are divided into genes I (epithelial genes), genes II (epithelial-mesenchymal genes) and genes III (mesenchymal genes), and false positive results caused by lack of part of the specific genes of the CTCs in a process that the CTCs enter peripheral blood for circulation are reduced; the method can be finished within eight hours, and a single copied mRNA hybridization probe is combined with a corresponding fluorescent probe by virtue of a signal amplification system, so that the detection sensitivity of in-situ RNA (Ribonucleic Acid) hybridization is remarkably improved.

A secretion-monitoring article for identifying a secreted biological fluid having a body with an absorbent material and least one pH determining member and a reagent associated with the absorbent material is disclosed. The article can be embodied as a swab, gauze, panty shield, hygienic napkin, diaper or interlabial absorbent structure and can be used to indicate the presence of amniotic fluid, or secretions associated with bacterial, parasite, fungal, or yeast infections without giving a false positive result upon exposure to urine. The present invention also teaches a pH indicator mixture and method of attaching the indicator to a substrate for use alone or integrated in an absorbent body and further teaches a method for monitoring the health condition of a person using the secretion-monitoring article.

A secretion-monitoring article for identifying a secreted biological fluid comprising a body with an absorbent material for absorbing a biological fluid secreted from a person and an indicator system. The indicator system comprises an indicator agent and an ion-balance reagent, wherein the indicator system provides an indication of physiological conditions associated with the pH or the buffer capacities of the biological fluid, which indication is stable for at least 48 hours, preferably at least 72 hours. The article can be embodied as a swab, gauze, shield, hygienic napkin, diaper or interlabial absorbent structure and can be used to indicate the presence of amniotic fluid, or secretions associated with bacterial vaginosis without giving a false positive result upon exposure to urine or drying out.

An improved technique provides location detection using wireless net-works such as Wi-Fi networks in a flexible, configurable manner that allows for variations in the environment and tracks target movement accurately in such an environment. Zones of different relative sizes and sensitivities can be defined, so as to vary the degree of resolution for different parts of the area being detected. Mechanisms are provided to take into account fluctuations in signal strength, and reduce the incidence of false positives resulting from incorrectly detecting zone or location changes due to fluctuations of signal strength. In addition, detection time can be configured for zone entry and / or exit. Self-adjustment based on heuristic analysis can also be implemented. Data can be sent or received based on the physical location as determined by the zone.

The invention discloses a cascading isothermal amplification based miRNA fluorescence detection kit and a miRNA fluorescence detection method. The target miRNA can specifically recognize and form a stable three-way crossing structure with a ternary probe through complementary hybridization of nucleic acids; a ternary primer in the three-way crossing structure performs strand displacement amplification (SDA) along a ternary template and generates a number of SDA template products; the SDA template product can open a difunctional hairpin probe to trigger nickase to perform signal amplification reaction finally; and a cyclophorase digestion molecular beacon can generate cascading amplified fluorescence signals. The kit can detect miRNA low to 100fM; and the detection method has superhigh specificity, can well distinguish highly homologous sequences at different mispairing positions and solves the difficult problem of false positive result caused by poor specificity in the existing detection method.

The invention relates to an anti-pollution portable gene detection method and device. The operation procedure comprises the steps that a PCR pipe containing amplification products is put into a device to conduct sealing, and by means of a series of simple manual operations, a detection result visible by eyes is obtained; target nucleic acid amplification products can be detected rapidly, nucleic acid amplification products can be prevented from being polluted, and a false positive result is avoided. Application can be achieved in the aspects of species identification on the gene level in the fields such as pathogen detection on clinical infectious diseases, food pathogenic microbe detection, agriculture, industry, customs and animal husbandry.

The invention provides a method for quickly and simply screening a CRISPR / Cas gene editing positive object. Compared with the prior art, the method disclosed by the invention has the characteristics that an Oligo DNA segment for constructing a knockout vector is used as a PCR (Polymerase Chain Reaction) primer for screening a target sample, and possible mutations on the DNA can be detected by using the feature that PCR can be efficiently initiated by completely matching a sequence at 3'-terminal of the primer with a template needed in the PCR reaction. By adoption of the method disclosed by the invention, experimental steps are reduced and design of extra PCR primers is not needed; the method is suitable for almost all experimental designs; special DNA endonuclease does not need to be purchased and a false positive result is hardly generated. Moreover, a sample for sequencing has higher qualification rate and qualified samples are hardly missed.

The present application discloses a method for detection of insertion deletion mutation based on second generation sequencing, a device and a storage medium. The method comprises the following steps:comparing a sample to be tested with a file of a reference genome to extract a set of candidate mutation sites with mutation allele frequency being greater than or equal to a threshold; filtering to remove sites in a short tandem repeat region; making detail statistics of comparison information of the mutation sites and comparison information surrounding the mutation sites, wherein the comparisoninformation includes InDel site and reference base support number, comparison quality, coverage depth, surrounding non-reference base and other insertion deletion mutations, surrounding read quality;and filtering to remove sites that do not reach the set threshold according to statistical information to obtain mutation results. The method does not require partial assembly, and filters second-generation sequencing data in advance to quickly eliminate most of false positive results caused by the comparison, reduces detection running time and computing resources, improves detection efficiency, has strong sensitivity and specificity, and can quickly and accurately detect InDel mutations.

The present invention provides a bodily fluid-testing composition for the determination and quantification of a specific ion concentration exceeding a pre-set threshold in a tested fluid, in which an ion oppositely charged to the ion in the bodily fluid is used to compete with an indicator reagent in order to compensate for variability in specific binding of the bodily fluid ions. The present invention further provides an article for monitoring of bodily fluids comprising a substrate and an absorbent material for absorbing the bodily fluid. The substrate includes a composition suitable for identification of a specific ion concentration in a tested fluid. The article can be used to indicate the presence of abnormal ammonium concentration in human urine, amniotic fluid leakage, or biogenic secretions associated with bacterial vaginosis, parasite infections, or deficiency of lactobacillus population, without giving a false positive result.

The present invention provides compositions, devices and methods suitable for the increased sensitivity and selectivity of binding assays thereby reducing false positive results without little or no reduction in the detection of true positives. The present invention is based on the novel discovery that an oxidative agent in the context of the device of the present invention results in decreased false positive reactivity with little or no reduction in true positive reactivity. The devices, compositions and methods of the present invention may be used, for example, to detect pathogens giving rise to endogenous urine antibodies include those organisms known to be causative agents in sexually-transmitted diseases and other diseases. The devices and methods of the present invention are also useful for various diagnostic procedures.

The invention discloses a high-throughput sequencing detection method used for HPV typing and integration. According to the method, the genes of current HPV subtypes are selected, in combination witha second-generation high-throughput sequencing technology, the type of HPV infected by a patient is detected more comprehensively, and the method overcomes the difficulties that a traditional detection method is low in accuracy rate, high in false positive result, low in repeatability and high in rate of missed diagnosis. In the field of molecular diagnosis, the mostly direct and specific technology is gene sequencing, and the second-generation high-throughput sequencing technology has the advantages of higher detection flux, higher sequencing speed, higher accuracy, lower cost and more abundant information contents compared with a classical Sanger sequencing method mostly adopted at present. According to the method, with the help of the second-generation high-throughput sequencing technology, accurate typing can be carried out on high-risk HPV and low-risk HPV, whether the integration of a human genome occurs is detected, accurate individual assessment is carried out on a detector, and the risk of a disease is prevented, so that the occurrence of a tumor is prevented.

The present invention relates to an accurate, sensitive, and efficient sequential or concurrently sequential method for molecular diagnosis of human papillomavirus (HPV)-based disease, where the method improves the accuracy and reliability of diagnostic and prognostic assessments of HPV-based disease. The method of the invention comprises a primary screen of a sample for HPV nucleic acids, followed by a secondary screen for molecular markers, such as proliferation and cell cycle control group protein markers. The sequential or concurrently sequential method significantly reduces the number of false positive results.

The present invention provides a method for preventing nucleic acid contamination and indicating a reaction result in a nucleic acid isothermal amplification reaction. With application of a LAMP reaction as a sample, fully refined paraffin having a melting point of 40-60 DEG C or semi-refined paraffin is adopted, the principle that the paraffin is at a liquid state at a LAMP reaction temperature (60-65 DEG C) and recovers to a solid state after completing the reaction and cooling to a room temperature is adopted to prevent pollution, and turbidity can be adopted to determine a result, or an indicator can be adopted to indicate an isothermal amplification reaction result. According to the present invention, the easily-prepared wax block having a special melting point is adopted, price is low, a solid state sealing effect is good, and permanent sealing can be achieved, such that contamination on amplification products can be avoided, the false positive result of the nucleic acid isothermal amplification reaction can be effectively prevented, and the method is applicable for all nucleic acid isothermal amplification reactions.

The invention discloses a method for exactly characterizing and evaluating flower aroma characteristics in cigarette aroma. Aroma substance quantitative data are acquired through an HS-GC-MS / MS detecting method, and a cigarette flower aroma note index H is obtained by calculating and establishing a threshold value of a corresponding aroma substance. The method is easy and convenient to operate, not easily disturbed by impurities, and accurate in detecting results. The selectivity and the sensitivity of GC-MS / MS are higher than those of GC-MS; the problems that the sensitivity of the GC-MS is low, the resolution is insufficient, the selectivity is low, false positive results are easily generated, and enough qualitative / quantitative information cannot be given and the like are avoided. According to the method, the flower aroma characteristics of a cigarette are described and expressed correspondingly from the perspective of material basis; the subjectivity of sensory evaluation is avoided; the flower aroma style of a cigarette product is characterized and evaluated objectively and comprehensively.

The invention discloses a nuclear acid probe marked with quantum dots and a preparation method and application thereof. Probes with different sequences are marked with quantum dots with different emission spectrum characteristics; the preparation method of the probe has the following steps: synthesizing numerous probes with different sequences and marking the probes with X; synthesizing numerous quantum dots with different emission spectrum characteristics and marking the dots with Y; integrating probes marked with X and quantum dots marked with Y through specificity of X and Y and carrying out coupling on the probes and the quantum dots; facilitating probes with different sequences to be marked with quantum dots with different emission spectrum characteristics; the probes are used for multicolor fluorescence in situ hybridization, spectral karyotype analysis and chromosome karyotype analysis, can improve sensitivity, repetitiveness and specificity of detection, simplify detection device, lower detection cost, increase detection speed and prevent false positive result from occurring.

Near-infrared Raman spectroscopy can be applied to identify preneoplastic lesions of the bronchial tree. Real-time in vivo Raman spectra of lung tissues may be obtained with a fiber optic catheter passed down the instrument channel of a bronchoscope. Using prototype apparatus, preneoplastic lesions were detected with sensitivity and specificity of 96 and 91% respectively. The use of Raman spectroscopy apparatus and methods in conjunction with other bronchoscopy imaging modalities can substantially reduce the number of false positive results.

The invention provide a ultra-performance liquid chromatogram-mass spectrum detection method for 23 types of drugs and mental disease resistant drugs in blood. The method comprises the following steps: 1) sample processing: employing an organic solvent for processing a sample through protein sediment; 2) primary screening detection: employing a ultra-performance liquid chromatogram-tandem mass spectrum (UPLC-MS / MS) multi-reaction monitoring (MRM) mode for primary screening detection; and 3) employing the ultra-performance liquid chromatogram-tandem mass spectrum (UPLC-MS / MS) multi-reaction monitoring (MRM) mode for reinspection of the positive sample through the primary screening in the step 2). According to physical and chemical properties of 9 types of drugs and 14 types of mental disease resistant drugs, during reinspection, the UPLC-MS / MS detection condition which is different with the primary screening detection is employed, different sample pretreatment methods are employed, so that the detection method can satisfy the rapid, sensitive and accurate requirements of primary screening detection, and misjudgement of false positive results can be reduced.

An indicator system including two pH sensitive indicators and a reagent is disclosed. The indicator system can be integrated into a number of products such as sanitary napkins or panty shields and thus can indicate the presence of amniotic fluid or secretions associated with vaginosis without giving a false positive result upon exposure to urine.

The invention relates to a DNA methylation biomarker composition for bladder cancer detection. The biomarker composition comprises any two or more of sequences shown in the formulas of SEQ ID NO.1 toSEQ ID NO.22, or any two or more of completely complementary sequences shown in the formulas of SEQ ID NO.1 to SEQ ID NO.22. The invention also relates to a detection kit for the methylation biomarkercomposition. The bladder cancer occurrence is discriminated and analyzed by using the composition in the co-methylation state of a plurality of specific methylation regions, the specific methylationcomposition has high sensitivity for discriminating the bladder cancer occurrence, and the detection method is simple, convenient and feasible. The primer pair composition of the kit overcomes the defect of false positive results caused by single methylation site detection mismatch in primer sequence design, and considers the interaction between multiple methylation biomarker primer and probe paircomposition.

The invention provides improved assays for detection of pregnancy. In the assays, pregnancy associated glycoproteins are analyzed in conjunction with progesterone analysis. The techniques of the invention overcome limitations in the prior art by reducing the rate of false positive results. The assays provided by the invention can be implemented to increase the efficiency of commercial animal breeding programs.

The invention provides a detection kit containing two anti porcine epidemic diarrhea virus monoclonal antibodies PEDV-McAB1 and PEDV-McAB2, two anti porcine transmissible gastroenteritis virus monoclonal antibodies and two anti porcine rotavirus monoclonal antibodies; the kit can be applied for simultaneous detection of porcine epidemic diarrhea viruses, porcine transmissible gastroenteritis viruses and / or porcine rotaviruses with non-diagnostic purpose, moreover, the detection sensitivity of the kit for simultaneous detection of two or three kinds of viruses is higher than that of single detection of one kind of virus, and false positive results are avoided.

The invention provides a same sequence primer transpositional nucleic acid amplification technology, which comprises the steps of: (1) linking the artificial sequence to the upstream of the target specific primer 5', and forming a chimeric primer; (2) taking the chimeric primer as an amplification target template to produce a secondary template with the two ends having artificial sequences; and (3) taking the artificial sequences with the same sequence of 65%-75% as the transpositional primer amplification secondary template. The technology is applicable to clinic molecular diagnosis, basically can utilize the primer design to prevent the false positive result from generating, and is particularly applicable to communicable disease nucleic acid detection and accurate diagnosis. The technology is particularly suitable to multiple PRC amplification technology, is nearly designed by aiming at the multiple PRC amplification technology, and the redundant and extraordinarily complicated primers of the multiple PRC amplification technology can only adopt the primer transpositional design to eliminate the nonspecific amplification of the primer polymer.

Compositions containing bacteriophages and methods of using bacteriophages in microorganism detection assays and microbial growth and plating media are disclosed. The lytic ability of these phages to control the growth of non-target populations provides superior sensitivity and specificity to detection assays and reduces false negative and false positive results. The removal of contaminating bacteria reduces the microbial competition for nutrients in the growth media thereby increasing the efficiency and productivity of the culture. The phage treatment of the sample increases the proportion of target microorganisms in the sample over contaminating bacteria thereby requiring less time for enrichment to obtain a significant signal improving overall signal to noise ratio in assays and providing for higher yield of end product in microbiological production systems.

The invention discloses a method for accurate characterization and evaluation of a milky aroma characteristic in a cigarette aroma. Quantitative data of aroma substances is obtained through an HS-GC-MS / MS detection method, and a cigarette milky aroma note index N is calculated and constructed through a corresponding aroma substance threshold. The method is simple to operate, difficult to interference of impurities, and accurate in detection results. The selectivity and the sensitivity of the GC-MS / MS are higher than those of GC-MS, and the problems that the GC-MS is low in sensitivity, lack of resolution rate, poor in selectivity, prone to production of false-positive results and unable to provide enough qualitative / quantitative information and the like are avoided. The cigarette milky aroma characteristic is correspondingly described and expressed from a substance base perspective, the subjectivity of sensory smoke panel tests is avoided, and the milky aroma style of cigarette products is objectively comprehensively characterized and evaluated.