181 results about "Nucleic Acid Probes" patented technology

The invention discloses a universal nucleic acid probe design method based on hybridization thermodynamics and kinetics, which comprises the following steps: 1) determining a target amplification region according to a fragment interval, generating a primer pair which meets the length requirement and covers a target fragment, calculating the Gibbs free energy change of nucleic acid hybridization by adopting an intelligent nucleic acid hybridization algorithm, and calculating the Gibbs free energy change of the target fragment according to the Gibbs free energy change; by combining chemical thermodynamics, kinetic parameters, sequence complementarity and enzymatic reaction characteristics, generating an optimal primer pair under a multi-dimensional constraint condition; and 2) on the basis of the generated optimal primer pair, generating a probe combination meeting a free energy difference threshold as a candidate pool, screening the probe combination with the highest objective function value from the candidate pool through an iterative process, and updating the candidate pool step by step until the primer pair and the probe combination with the highest objective function value are output. By introducing an intelligent algorithm and combining a thermodynamic model, a dynamic model and specificity evaluation, an optimal primer and probe combination is automatically generated, and the stability and reliability of design are ensured.

The present disclosure relates, in some aspects, to methods and compositions for analyzing a biological sample. In some aspects, the methods comprise use of a probe set comprising a first and second polynucleotide which hybridize to a target nucleic acid in the biological sample and form a circularized probe. In some aspects, the methods and compositions provided herein improve the detection of nucleic acids in a biological sample.

The invention discloses a dual-recognition-framework nucleic acid probe, a preparation method and application, the dual-recognition-framework nucleic acid probe comprises a DNA tetrahedron, and a dual-recognition module and a fuel amplification module which are connected to the vertex of the DNA tetrahedron through complementary pairing of bases, ATP recognition protection and dual-target response are introduced, and the dual-recognition-framework nucleic acid probe is obtained through sequential opening of internal and external locks. The occurrence of false positive conditions can be reduced, and the specificity is effectively improved; signal amplification is realized by virtue of abnormal APE1 expression of tumor cells, so that a fluorescence signal for miRNA detection is increased, and the sensitivity and the imaging signal-to-noise ratio are effectively improved; the preparation is easy; the use is convenient; complicated equipment is not needed. The method can be applied to a target nucleic acid detection reagent or an imaging or positioning reagent of cells, tissues or organs containing target nucleic acid.

The embodiment of the invention provides a connecting unit for chemical modification of a nucleic acid end group, a preparation method of the connecting unit and a nucleic acid probe. The connecting unit for chemical modification of the nucleic acid end group has a triethylene glycol structure, and the connecting unit has the following structure. Therefore, the connecting unit with the triethylene glycol structure is relatively simple in synthesis process, relatively high in yield, efficient in synthesis, good in nucleic acid end group chemical modification effect, applicable to connection of various types of probe molecules and nucleic acid molecules, capable of simply and efficiently preparing nucleic acid probes and wide in application range.

The present invention belongs to the technical field of immunochromatography. Provided are a streptavidin multimer, and a preparation method therefor and the use thereof. The prepared streptavidin multimer has a strong affinity for a biotin / fluorescein nucleic acid probe. A nucleic acid test strip prepared with the prepared streptavidin multimer can realize rapid and high-sensitivity detection of a sample to be detected. Results can be obtained in 5 minutes, the false positive rate can be reduced, and the cost of the nucleic acid probe is reduced, which is convenient for non-professional technicians to easily and accurately judge the results.

The invention provides a primer / probe composition for capillary electrophoresis analysis, a detection method and application. The primer / probe composition comprises a forward primer, a reverse primer and a nucleic acid probe, the 5'end of the nucleic acid probe carries a fluorescent label, and both the forward primer and the reverse primer do not carry the fluorescent label. Different targets are identified by detecting the nucleic acid probe, so that the length of an amplification product is not limited, only the nucleic acid probe carries a fluorescence signal without generating a non-specific fluorescence signal, the generation of a supersaturated fluorescence signal can be effectively prevented by using the nucleic acid probe with a specific concentration, the fluorescence signals among different targets do not interfere with each other, and the detection sensitivity is high. And multicolor fluorescence can be used at the same time.

The invention provides a nucleic acid probe, a primer group, a kit, a detection method and application, and relates to the technical field of biology. The nucleotide sequence of the nucleic acid probe is as shown in SEQ ID NO. 1; wherein the 3'end of the nucleic acid probe is modified with MGB, and locked nucleic acid is modified at a base position corresponding to the difference between the swine fever wild strain and the swine fever vaccine strain in the nucleotide sequence. According to the nucleic acid probe, a specific sequence is utilized to precisely target a swine fever wild strain, and locked nucleic acid modification is introduced at a differential site, so that the recognition capability on single-base mismatch is remarkably enhanced, non-specific binding to a vaccine strain is thoroughly blocked, and false positive interference is eliminated; and 3 '-terminal MGB modification is matched to improve the binding stability and sensitivity, so that the efficient and accurate identification of the swine fever wild strain under the immune background is ensured.

The present invention generally relates to systems and methods for imaging or determining nucleic acids, for instance, within cells. In some embodiments, the transcriptome of a cell may be determined. Certain embodiments are directed to determining nucleic acids, such as mRNA, within cells at relatively high resolutions. In some embodiments, a plurality of nucleic acid probes may be applied to a sample, and their binding within the sample determined, e.g., using fluorescence, to determine locations of the nucleic acid probes within the sample. In some embodiments, codewords may be based on the binding of the plurality of nucleic acid probes, and in some cases, the codewords may define an error-correcting code to reduce or prevent misidentification of the nucleic acids. In certain cases, a relatively large number of different targets may be identified using a relatively small number of labels, e.g., by using various combinatorial approaches.

The present invention generally relates to systems and methods for imaging or determining nucleic acids in cells or other samples. In some cases, the transcriptome of a cell may be determined. Certain embodiments are generally directed to determining nucleic acids and other targets in a sample at relatively high resolutions. For instance, nucleic acid probes may be applied to sample, and binding of the nucleic acid probes to a target may be amplified using primary and secondary amplifier nucleic acids. In some cases, there is a maximum number of amplifier nucleic acids that can be bound to a target, e.g., the binding is saturatable, and cannot grow indefinitely, even in the presence of abundant reagents. This may be advantageous, for example, for controlling the brightness of each binding event, controlling the size of the amplified regions (e.g., during imaging), and / or for limiting the degree of amplification noise (i.e. the final variation in amplified signal from molecule to molecule), etc. In addition, in some embodiments, the primary and / or secondary amplifier nucleic acids may be formed from only 3 of the 4 naturally-occurring nucleotides, which may result in less secondary structure, faster binding rates, etc. These properties can in some cases facilitate the rapid design of multiple orthogonal amplification sequences, allowing the extension of such an approach to many distinct molecular targets.

The invention discloses a multi-nucleic acid probe rapid modification and multi-target detection device based on electric field regulation and control. An instrument main body in the device is integrated with an automatic liquid path system and a micro electrochemical workstation module, and is used for realizing programmable reagent and sample conveying and multi-channel electrochemical measurement. The detachable sensing chip is formed by bonding a microelectrode array chip and a micro-fluidic chip, and is switched through a PCB (Printed Circuit Board) to realize plug and play. According to the present invention, the positive suction-negative discharge strategy of the electric field is utilized, the preferred positive potential is applied to the target electrode to efficiently attract the probe, and the preferred negative potential is applied to the non-target electrode to inhibit the non-specific adsorption so as to achieve the spatial selective rapid fixation and the accurate density regulation and control of the multi-nucleic acid probe in the extremely short time; the device can be used for quantitatively detecting various body fluid disease markers in a plurality of urine samples at the same time in single operation, and an efficient, accurate and portable multi-marker comprehensive analysis solution is provided for early screening and instant diagnosis of tumors.

The invention relates to a streptavidin polymer as well as a preparation method and application thereof, and belongs to the technical field of immunochromatography. The prepared streptavidin polymer has strong affinity with a biotin / fluorescein nucleic acid probe, nucleic acid test paper prepared from the prepared streptavidin polymer can realize rapid and high-sensitivity detection on a detected sample, a result can be obtained within 5 minutes, the false positive rate can be reduced, the cost of the nucleic acid probe is reduced, and the method is suitable for popularization and application. And non-professional technicians can conveniently, easily and accurately judge the result.

The invention belongs to the technical field of biochemical detection, and particularly relates to a micro-fluidic chip PSMA prostate cancer circulating tumor cell immunoenrichment detection kit and a preparation method thereof. According to the kit, an EpCAM antibody, a Vimentin antibody and a double-site PSMA capture combination are fixed in a chip channel through a streptavidin-biotin system, double enrichment of epithelial and mesenchymal CTCs is achieved, PSMA targets are recognized through combination of an aptamer and the antibody, and the detection specificity and sensitivity are improved. Competitive oligopeptides are further introduced to block non-specific binding sites on the surfaces of leukocytes and reduce false positive. By combining a multiple fluorescent chromosome system and a double-antibody nucleic acid probe signal amplification strategy, accurate recognition and quantification of CTC and PSMA positive cells are realized. The scheme is suitable for early screening, curative effect evaluation and relapse monitoring of prostate cancer, and has a good clinical application prospect.

The present invention generally relates to systems and methods for imaging or determining nucleic acids, for instance, within cells. In some embodiments, the transcriptome of a cell may be determined. Certain embodiments are directed to determining nucleic acids, such as mRNA, within cells at relatively high resolutions. In some embodiments, a plurality of nucleic acid probes may be applied to a sample, and their binding within the sample determined, e.g., using fluorescence, to determine locations of the nucleic acid probes within the sample. In some embodiments, codewords may be based on the binding of the plurality of nucleic acid probes, and in some cases, the codewords may define an error-correcting code to reduce or prevent misidentification of the nucleic acids. In certain cases, a relatively large number of different targets may be identified using a relatively small number of labels, e.g., by using various combinatorial approaches.

The invention relates to the technical field of molecular diagnosis and graphic processing, in particular to an electronic microarray chip dot matrix negative and positive judgment method based on an ISFET sensor. A chip hole site corresponds to an ISFET sensor, and after a hole bottom specific nucleic acid probe and a target sequence are hybridized and extended, the voltage of the sensor is changed. The method specifically comprises the following steps: data preprocessing: filtering median values of multi-frame electric signals of a hole site and taking a mean value; the dot matrix identification comprises the steps of threshold demarcation, Canny edge detection, circular Hough transform, optimal circle screening by Kdtree, array numbering and abnormal deletion processing to position a dot matrix; and calculating a result, extracting a signal difference value of the D1 stage and the D4 stage, evaluating numerical values of the positive quality control array and the to-be-detected sample array through a numerical value of the negative quality control array, and judging a final calculation result. According to the method, response changes are rapidly analyzed through image recognition, false detection and missing detection caused by numerical value differences in different arrays are reduced through multiple times of detection, and the detection accuracy is improved by selecting the most possible area through tickets.

The present disclosure is generally directed to anchoring bridge nucleic acid probes in a polymer matrix, which are configured to hybridize to cellular nucleic acid, embedding in a polymer matrix, clearing cellular components including the cellular nucleic acid, contacting the anchored bridge probes with primary probes that hybridize with the bridge probes and imaging. The disclosure describes methods for imaging cellular RNA in an RNase insensitive method.

The invention discloses a preparation method of a space chip, the space chip and application of the space chip, the preparation method comprises the following steps: hybridizing: connecting a single-stranded nucleic acid molecule to the surface of a solid-phase substrate, the single-stranded nucleic acid molecule comprises a first fixed sequence, a space bar code sequence, a sequencing primer binding sequence and a second fixed sequence, the surface of the solid-phase substrate of the chip substrate is connected with a first probe, and the first probe comprises a first fixed sequence complementary sequence and a second fixed sequence complementary sequence; carrying out ring closing to enable the single-stranded nucleic acid molecules to form annular nucleic acid molecules; carrying out rolling circle amplification; sequencing to obtain sequence information of the space bar code sequence; synthesizing single-stranded nucleic acid molecules by taking the rolling circle amplification product as a template to obtain a single-stranded nucleic acid molecule library; fixing and clustering: fixing the single-stranded nucleic acid molecule library on the surface of a solid-phase substrate to form a single-stranded nucleic acid molecule cluster. According to the invention, the chip with the nucleic acid probe carrying spatial position coordinate information can be prepared.

The present disclosure relates to finely modulated ultra-specific nucleic acid hybridization probes. The present invention provides compositions and methods for highly specific nucleic acid probes and primers. The probe system includes a complementary strand and a protective strand to partially form a double-stranded probe. The reaction standard free energy ([delta] G DEG rxn = [delta] G DEG t-TC-[delta] G DEG nh-PC + ([delta] G DEG v-TC-[delta] G DEG h-PC)) of hybridization between the probe and the target nucleic acid determined by formula 1 is about-4 kcal / mol to + 4 kcal / mol. Alternatively, the reaction standard free energy of hybridization between the probe and the target nucleic acid determined by Formula 1 is within 5 kcal / mol of the standard free energy determined by Formula 2 (-R [tau] ln (([P] 0-[C] 0) / [C] 0)), the term [P] 0 of Formula 2 being equal to the concentration of the protective strand, and the term [C] 0 of Formula 2 being equal to the concentration of the complementary strand. In addition, the present invention provides a method for the immediate fine modulation of a reaction using the probe of the present invention.

To provide methods for imaging or determining nucleic acids in cells or other samples.SOLUTION: A method comprises: exposing a sample to nucleic acid probes; exposing the nucleic acid probes to primary amplifier nucleic acids able to bind to the nucleic acid probes; determining a distribution of the nucleic acid probes within the sample using fluorescence; and creating codewords based on the fluorescence distribution within the sample.SELECTED DRAWING: Figure 1-2

The invention discloses a human papilloma virus mRNA (messenger ribonucleic acid) detection kit for auxiliary diagnosis of cervical cancer patients. The human papilloma virus mRNA detection kit comprises a nucleic acid probe group and a series of nucleic acid probes AMP1-AMP5, wherein the nucleic acid probe group is used for being combined with a human papilloma virus mRNA target, and the nucleic acid probes AMP1-AMP5 are used for signal amplification. The human papilloma virus mRNA detection kit provided by the invention can assist pathologists in identifying and diagnosing cervical cancer patients, and provides a basis for clinicians to formulate a therapeutic schedule.

The invention discloses a synthesis method of 2 '-O-methyladenosine, and belongs to the technical field of nucleoside synthesis and medicinal chemistry. According to the method, xylose which is rich in source is taken as an initial raw material, eight-step reaction including acetalation protection, acetylation, glycosylation, deacetylation, methylation, deacetalation protection, Mitsunobu reaction and secondary deacetylation is performed, reaction conditions of each step are accurately controlled, and finally, a target product is synthesized. The method has the advantages of high methylation reaction regioselectivity, mild reaction conditions, cheap and easily available raw materials and controllable cost, and overcomes the problems of poor methylation reaction regioselectivity, harsh reaction conditions and high cost in the existing synthesis method. The obtained product has important application value in the fields of research and development of antiviral drugs, design of nucleic acid probes and the like.

A method for measuring an oligonucleotide which is simpler and more sensitive and has excellent specificity and quantitative capability compared to the conventional measurement method is provided. Moreover, a method for measuring an oligonucleotide having excellent specificity which can distinguish the intact target oligonucleotide (unchanged form) and a metabolite thereof and detect the unchanged form only is provided. In a hybridization method using a capture probe and an assist probe, by inserting a spacer between a solid phase and a nucleic acid probe contained in the capture probe, it becomes possible not only to detect the target oligonucleotide in a sample but also to distinguish from a metabolite of a nucleic acid drug.

An L-form ribonucleic acid (L-RNA) aptamer-antisense oligonucleotide (ASO) conjugate comprise the L-RNA aptamer, which comprises a ribonucleic acid sequence. The ASO comprises a deoxyribonucleic acid sequence selected from a group. A method of imaging amyloid precursor protein (APP) rG4 in a cell comprising transfecting the cell with a messenger RNA of APP, permeating the cell, contacting the permeated cell with a cyanine3 (Cy3) labeled APP nucleic acid probe and the L-RNA aptamer-ASO conjugate, and subjecting the product to fluorescence microscopy analysis to produce an image of the APP rG4 in the cell.

Described herein is an immobilization-free, electrochemical method of detecting a target DNA sequence in a sample. The method includes: incubating the sample with a detection mixture, applying an electric field including an alternating current electric field and a direct current offset to the detection mixture to concentrate nucleic acids in the sample and the nucleic acid probe on a positively charged working electrode, wherein a Class 2 Cas protein trans-cleaved electroactive probe is released from the nucleic acid probe when the target DNA is present in the sample and diffuses toward a negatively charged electrode; and measuring the current as potential is applied, wherein detection of a current in the detection mixture indicates the presence of the target DNA sequence in the sample.

The invention discloses an exosome detection method based on double-hairpin nucleic acid probe assembly, and belongs to the technical field of exosome detection. The exosome detection method comprises the following steps: step 1, constructing a multi-element hairpin probe H1; step 2, constructing a multi-element hairpin probe H2; 3, preparing a probe; 4, multi-element signal probes are assembled, in the step 4, three groups of H1 probes and H2 probes are arranged in total, the proportion of the first group of H1 probes and 400 nM H2 probes is 80 nM, the proportion of the second group of H1 probes and 300 nM H2 probes is 80 nM, and the proportion of the third group of H1 probes and 350 nM H2 probes is 80 nM; according to the exosome detection method based on double-hairpin nucleic acid probe assembly, parallel detection of different exosome surface markers can be achieved by constructing multiple hairpin probes H1 and H2, and meanwhile the requirements for high specificity and stability are met.

The present disclosure relates in some aspects to methods and systems for analyzing a biological sample comprising contacting the biological sample with a nucleic acid probe non-covalently associated with a monomethine cyanine dye or salt thereof. In some aspects, a signal associated with the monomethine cyanine dye or salt thereof is detected to determine the location of a target analyte in the biological sample.

To provide an improved probe achieving enhanced brightness and producing a further lowered signal-to-noise ratio.SOLUTION: A compound useful as a nucleic acid probe is disclosed. In some embodiments, the compound has the following structure (I), or is a stereoisomer, tautomer, or salt thereof. Methods relating to preparation and use of such a compound are also provided.SELECTED DRAWING: None

The invention discloses a biochemical sensing system based on a catalytic hairpin assembly circular reaction and a G quadruplex-heme DNA enzyme formation reaction. The biochemical sensing system is used for photoelectrochemical colorimetric detection of circular RNA (circRNA). After the nucleic acid probe H1 is combined with the nano magnetic beads (MNPs), the circRNA is specifically recognized, and an MNPs / H1 / circRNA compound is formed; the MNPs / H1 / H2 compound reacts with a probe H2 to form an MNPs / H1 / H2 compound; the H1 probe and the H2 probe release a part of sequences by utilizing restriction endonuclease cutting, and the unreleased sequences are combined with hemin to form G quadruplex-heme DNA enzyme with peroxidase-like activity; through cascade catalytic reaction, the color of a solution of a reaction system is changed, the linear relation between the absorbance of the solution and the concentration of circRNA in the solution is fitted, and an effective method for carrying out photoelectrochemical colorimetric detection on circRNA is developed.

The invention belongs to the technical field of small molecule detection, and relates to a nucleic acid-based algal toxin on-site rapid quantitative detection paper chip device and a detection method thereof. A reaction area of the paper chip device is coated with an aptamer c-DNA and a fluorescent group labeled-DNA, and a reading area of the paper chip device is coated with a capture nucleic acid probe d-DNA; the nucleic acid sequence of the aptamer c-DNA is as shown in SEQ ID NO.1, and the 5'end of the c-DNA is marked with biotin; the nucleic acid sequence of the capture nucleic acid probe is shown as SEQ ID NO.1, the nucleic acid sequence of the capture nucleic acid probe is shown as SEQ ID NO.2, the 5'end of the capture nucleic acid probe is marked with an FAM fluorophore, the nucleic acid sequence of the capture nucleic acid probe d-DNA is shown as SEQ ID NO.3, and the 5 'end of the capture nucleic acid probe d-DNA is marked with biotin. The whole detection process does not exceed 10 minutes, the cost is low, and rapid on-site quantitative detection of algal toxin in water is achieved.