22 results about "Bacterial nucleic acid" patented technology

The invention belongs to the field of biological detection, and discloses an exosome RNA detection composition based on positive and negative targets and a use method thereof, the composition comprises two positive targets and one negative target: the positive target A is miRNA stably expressed in exosome and is used for reflecting the expression level of small RNA; the positive target B is typical mRNA and is used for evaluating the quality of the long-fragment RNA; the negative target C is bacterial 16S rRNA and is used for identifying bacterial nucleic acid pollution in a sample. The method combines III-generation reverse transcriptase and HotStart Taq enzyme to construct a qPCR system, has high sensitivity and specificity, and is suitable for rapid detection of trace RNA. Whether the exosome RNA is suitable for downstream analysis or not can be judged by acquiring the Cq values of the three types of targets and setting a reference range. According to the invention, the integration of quality control, quantification and pollution identification of the exosome RNA is realized.

To provide compositions and methods for detecting bacterial nucleic acids and diagnosing bacterial vaginosis.SOLUTION: Disclosed is a method for diagnosing bacterial vaginosis in a subject comprising performing an assay to detect one or more of Lactobacillus spp., Atopobiumvaginae, and Gardnerallvaginalis in a sample of the subject. Also disclosed are compositions and methods for detecting Lactobacillus spp., Atopobiumvaginae, and / or Gardnerallvaginalis nucleic acids in a sample.SELECTED DRAWING: None

The disclosure provides extraction control methods for use with molecular bacterial load assays (the 'MBLA'). The MBLA may be used to quickly (e.g. in about four hours), detect and enumerate the number of vaiable bacteria in, for example, a sample. The disclosed extraction control methods provide improved MBLAs and may be applied to a broad range of different MBLAs may find application as a means to accurately adjust for bacterial loss during a target bacterial nucleic acid extraction procedure.

This invention discloses a magnetic sensor device based on DNA binding force and its application in bacterial detection. This invention relates to the field of magnetic sensing technology, specifically to a magnetic sensor device based on DNA binding force and its application in bacterial detection. The device for biological sample analysis of this invention includes a magnetic sensor, a DNA walking strand (WS), a nucleic acid aptamer specific to the biological sample to be detected, and an exonuclease III. The magnetic sensor is an array containing N types of double-stranded DNA molecules named TP-AP-FP immobilized on a substrate and a magnetic solid modified with streptavidin. When used for bacterial detection, this invention eliminates the need for bacterial labeling and bacterial nucleic acid extraction, allowing direct interaction with the bacterial surface. It is simple to operate, saves time, has high accuracy, can construct magnetic sensors for detecting different targets, and is versatile with a wide detection range.

Provided is a method for nucleic acid reduction in a bacterium to less than about 5 wt % of a total dry weight of the bacterium, the method comprising culturing the cells of the at least one bacterium in a fermentation medium to obtain a fermentation medium comprising a biomass; heating the biomass to a temperature of at least 70° C. for at least 10 minutes; and washing the biomass. Also provided are food components, food ingredients and foods or beverages comprising single cell proteins produced from such bacteria.

The invention relates to the technical field of biology, in particular to a bacterial nucleic acid extraction kit and application thereof.The bacterial nucleic acid extraction kit comprises a bacterial lysis solution, cellulose microspheres, eluent and a matched nucleic acid extraction device and can efficiently lyse cell walls of gram-negative bacteria and gram-positive bacteria and rapidly purify nucleic acid; the time consumed by the whole nucleic acid extraction link does not exceed 10 minutes, the downstream PCR detection sensitivity can reach 10 <-9 > ng / mu L, and the timeliness and reliability of nucleic acid extraction are remarkably improved.

The invention discloses a method for detecting spatial bacterial species on a tissue slice. According to the method, a microfluidic device with an orthogonal microchannel array is installed on the surface of a tissue slice on a glass slide, space tag X and Y polynucleotides are loaded respectively, a two-dimensional space coordinate system is formed on a tissue plane, and space coding of bacterial nucleic acid signals is achieved. Sequence information and spatial positioning data of bacterial species can be obtained through reverse transcription, template conversion, PCR amplification and high-throughput sequencing. According to the method, a bacterial 16S rRNA sequence is taken as a detection target, and a streptavidin magnetic bead enrichment and biotin labeling system is combined, so that parallel detection of various bacterial species can be realized. Compared with the traditional FISH and array capture method, the method has the advantages of high detection flux, resolution of about 50 microns, low cost, simplified operation process and the like, and is suitable for research of bacterial community space structures in host tissues and analysis of microbial ecological distribution.

A rapid sterility test method that reduces inhibition of the nucleic acid amplification reaction of target nucleic acid due to human nucleic acid. The rapid sterility test method can detect the presence of bacterial nucleic acid included in a test sample including human nucleic acid by a nucleic acid amplification method, where an oligoset that is used in the nucleic acid amplification method includes (1) one or more probes selected from the group consisting of a probe group PM1, a probe group PM2, and a probe group PM3 and (2) one or more reverse primer in a primer group RM.

The invention belongs to the technical field of biological detection, and particularly relates to a sample pretreatment method for targeted sequencing of high-sensitivity and broad-spectrum respiratory pathogenic microorganisms. The sample pretreatment method comprises the following steps: sequentially carrying out grinding wall breaking and enzymolysis wall breaking on a to-be-detected sample; the grinding and wall breaking time is 4-6 minutes, or / and an RNase inhibitor is added into an initial grinding and wall breaking system. The method can well balance the pathogens difficult to break walls and the pathogens easy to break walls but relatively difficult to stabilize the released nucleic acid in a balanced and high detection rate under the same reaction condition. According to the method, on the premise of ensuring the extraction efficiency of the nucleic acid of the bacteria difficult to break walls, the most suitable mechanical wall breaking time of pathogens easy to break walls but relatively difficult to stabilize the nucleic acid is selected, and the stability and detection of the RNA extraction process are remarkably improved by using the RNase inhibitor.

The application relates to the technical field of nanomaterial preparation, in particular to a ZnO@Fe3O4 urchin-like magnetic bead and a preparation method and application thereof. The method comprises the following steps: preparing a seed layer solution: dissolving zinc acetate dihydrate and sodium hydroxide in anhydrous ethanol; preparing a growth solution: dissolving zinc nitrate hexahydrate, hexamethylenetetramine and polyethylene imine in deionized water and uniformly mixing by ultrasonic; taking magnetic beads and dispersing the magnetic beads in the seed layer solution, ultrasonic mixing for 3-10 min, and then mechanically stirring for 1.5-2.5 h; after stirring, incubating at 130-180 DEG C for 1.5-3 h; collecting the magnetic beads, discarding the solution, and cleaning with deionized water; transferring to the growth solution, ultrasonic mixing for 3-7 min, and then incubating at 80-100 DEG C for 1.5-2.5 h; washing the product and drying. The urchin-like magnetic bead can mechanically break bacteria, is simple and easy to operate, saves cost, is safe and reliable, and makes the bacterial nucleic acid extraction work more efficient.

The invention relates to the technical field of biology, in particular to a lysis solution for rapidly extracting bacterial nucleic acid and a rapid nucleic acid extraction method based on the bacterial lysis solution and magnetic bead separation and enrichment. The lysate is prepared from 50m of Mtris (pH = 7.5), 20mM of EDTA (Ethylene Diamine Tetraacetic Acid), 0.7 M of NaCl, 1.5 M of guanidine isothiocyanate, 1M of guanidine hydrochloride, 0.2 percent of SDS (Sodium Dodecyl Sulfate), 1.5 percent of Tween-20, 1.5 percent of Triton X-100 and 1 percent of PEPPG F68. The extraction method comprises the steps of sample pretreatment and cracking, magnetic bead combination, magnetic bead washing, magnetic bead redissolution and magnetic bead separation, and can be used for treating Gram-positive bacterium and Gram-negative bacterium samples. Silicon hydroxyl magnetic beads with specific particle sizes are adopted, a 2mM NaOH solution is used for washing, and a Tris-HCl (pH = 7.9) solution is used for redissolving. The lysate can be used for preparing a reagent for rapidly extracting bacterial nucleic acid, the extraction method can be applied to bacterial detection or molecular biology experiments, the nucleic acid extraction time is effectively shortened to be within 10 minutes, and an efficient and reliable technical means is provided for related research and detection work.

The invention provides a ship ballast water bacterium digital microfluidic detection chip and method based on a laser direct writing technology. The device comprises a digital micro-fluidic liquid drop control chip and an electrochemical sensor, the digital micro-fluidic chip comprises a substrate, a driving electrode, a dielectric layer, a hydrophobic layer, a dielectric layer and an upper polar plate structure from bottom to top, and the electrochemical sensor comprises a working electrode, a reference electrode and a counter electrode. An electrode of the electrochemical sensor is processed in a corresponding area of an upper polar plate of the digital micro-fluidic chip through a multilayer laser direct-writing ITO etching method, and a local hydrophobic barrier is made. When bacteria detection is carried out, a purified bacteria nucleic acid sample is placed on the DMF chip and is respectively mixed with Mix buffer, respective specific Lamp primers of three bacteria and electrochemical signal molecules MB, isothermal amplification is carried out at 65 DEG C, and finally amplified products are transferred to an electrochemical chip detection area for quantitative detection. According to the invention, synchronous, efficient and quantitative detection of three typical ballast water bacteria on the DMF platform can be realized.

Described herein are compositions, methods, and kits for detecting diarrhea-causing pathogens from a patient, food, or environmental sample. One embodiment described herein is a primer pair and probe for a multiplex polymerase chain reaction (PCR)-based assay for the detection of diarrhea-causing pathogens, such as Campylobacter spp., Salmonella spp., Shigella spp. / Enteroinvasive Escherichia coli (EIEC), Escherichia coli stx1 / Shiga toxin A, or Escherichia coli stx2 / Shiga toxin B. Other embodiments include methods and kits for detecting diarrhea-causing pathogens.

Disclosed are methods for diagnosing Bacterial Vaginosis in a subject comprising performing an assay for the detection of any one or more of Lactobacillus sp., Atopobium vaginae, and Gardnerella vaginalis in a subject sample. Also disclosed are compositions and methods for detecting Lactobacillus sp., Atopobium vaginae, and / or Gardnerella vaginalis nucleic acid in a sample.

A method for detecting bacterial nucleic acids is provided. The method includes the steps of: providing an extended gate field effect transistor (EGFET) having a sensing region; fixing a nucleic acid probe on the sensing area, wherein the nucleic acid probe has specificity for gram-negative bacteria or gram-positive bacteria; providing a control group sample on a sensing region of the EGFET; detecting a first electrical signal of the EGFET after the control group sample is provided onto a sensing region of the EGFET; providing a sample on a sensing region of the EGFET; detecting a second electrical signal of the EGFET after the sample is provided onto a sensing region of the EGFET; and comparing the first electric signal with the second electric signal to judge whether bacterial nucleic acid exists in the sample.

The invention provides a method for identifying and eliminating pollutants during quantification of microbe cfDNA in peripheral blood, which comprises the following steps: S1, screening common bacteria of peripheral blood and esophageal-gastric junction tumor, and extracting bacterial nucleic acid; s2, designing a corresponding primer probe combination according to the specific nucleic acid sequence of the bacteria, and carrying out multiple amplification on the bacterial nucleic acid by utilizing fluorescent quantitative PCR (Polymerase Chain Reaction); s3, carrying out statistical classification on the amplified specific nucleic acid sequence in the step S2 by utilizing R statistical software decontam to obtain a statistical classification program; the method comprises the following steps: adding artificially synthesized exogenous DNA during preparation of a sample of microorganism cfDNA in peripheral blood, and setting an identification sample confusion method; and S4, identifying and eliminating pollutants through a statistical classification program, and quantifying the microbe cfDNA in the peripheral blood. The method disclosed by the invention can be used for accurately, quickly and conveniently detecting the bacterial nucleic acid in the peripheral blood, identifying and eliminating polluted samples at the same time, and avoiding false positive during detection.

The application discloses a kit and a method for detecting blood stream infection bacterial nucleic acid by using a multiple probe melting curve method, and utilizes a multiple probe melting curve technology to adopt four different fluorescent probes to carry out fluorescent PCR combined with multiple melting curves, and develops an eight-target bacterial detection kit for common eight kinds of bacteria in blood stream infection. The application has the sensitivity and the specificity of the fluorescent quantitative PCR, and has a larger detection flux than the fluorescent quantitative PCR method, is more convenient to operate, and is lower in cost.

The invention discloses a primer group and a kit for high-throughput targeted detection of swine pathogens and drug-resistant genes and application of the primer group and the kit. The primer group consists of 248 pairs of primers with nucleotide sequences as shown in SEQ ID NO: 1-496. According to the primer group, the kit and the detection method, specific amplification is performed on key areas of 55 pathogenic target genes and 77 drug-resistant genes of pigs, and the primer group, the kit and the detection method have the following remarkable advantages: 1) high precision and specificity: sequencing is performed on a specific area, so that the detection accuracy is remarkably improved, low-abundance pathogenic bacterium nucleic acid can be effectively detected, and early diagnosis is assisted; 2) high efficiency and economy: parallel detection of various pathogenic bacteria and drug-resistant genes can be realized through a single experiment, and the detection flux is greatly improved; compared with whole genome sequencing, the cost of targeted sequencing is lower; 3) the method is simple, convenient and universal, the data analysis complexity is remarkably reduced, the method is suitable for various clinical samples such as blood, tissues and secretions, and a unified and efficient detection scheme is provided for different sample types.

Provided is a method for nucleic acid reduction in a bacterium to less than about 5wt% of a total dry weight of the bacterium, the method comprising culturing the cells of the at least one bacterium in a fermentation medium to obtain a fermentation medium comprising a biomass; heating the biomass to a temperature of at least 70ºC for at least 10 minutes; and washing the biomass. Also provided are food components, food ingredients and foods or beverages comprising single cell proteins produced from such bacteria.

To provide a composition and method for detecting bacterial nucleic acids and diagnosing bacterial vaginosis. [Solution] A method for diagnosing a target bacterial vaginosis is disclosed, comprising performing an assay to detect one or more of the following species in a target sample: Lactobacillus, Atopobium vaginae, and Gardneralla vaginalis. Also disclosed are compositions and methods for detecting the nucleic acids of Lactobacillus, Atopobium vaginae, and / or Gardneralla vaginalis in a sample.

The present application relates to the technical field of molecular markers, and particularly relates to a porcine epidemic diarrhea virus (PEDV) bacterium-like particle and a preparation method thereof, which takes S1 genes and COE genes of Guangxi PEDV epidemic strains as target genes, and successfully expresses fusion proteins S1-PA and COE-PA fused with anchor hook proteins PA by using an insect cell-baculovirus expression system; meanwhile, lactic acid lactobacillus MG1363 is treated by heat and acid to remove bacterial nucleic acids and proteins, and GEM particles are successfully prepared, and the fusion proteins S1-PA and COE-PA are successfully displayed on the surfaces of the GEM particles to obtain S1-GEM and COE-GEM particles, the two kinds of particles are mixed with GEL-01 adjuvant to prepare two kinds of bacterium-like particle vaccines, and the vaccines are used for immunization of mice, and it is confirmed through immunization routes, immunogens and immunization doses that 24 mu g COE-GEM can achieve the optimal immunization effect for the mice immunized by nose drops.

Disclosed herein includes a nanoplasmonic sensor for molecular characterization of urinary tract infections. In some embodiments, the nanoplasmonic sensor can also be used at the point-of-care. The nanoplasmonic sensor utilizes an optical phenomenon that occurs between a metal nanoparticle and a dielectric—localized surface plasmon resonance (LSPR)—for the detection of bacterial nucleic acids. In some embodiments, the spectral peak shift is a function of target sequence concentration.