11 results about "Propidium iodide" patented technology

The invention provides a cell activity detection method based on fluorescence labeling, and relates to the technical field of cell analysis. The cell activity detection method based on fluorescence labeling comprises the following steps: S1, co-incubating a cell sample to be detected with a mixed solution of propidium iodide, a JC-1 mitochondrial membrane potential dye, a DCFH-DA active oxygen probe, a Caspase-3 / 7 activated substrate and a Hoechst nuclear dye, completing synchronous multiple labeling, and generating a multi-labeled cell sample, S2, detecting the cell activity based on the multi-labeled cell sample, five-channel full-automatic scanning is carried out through a high-content imaging system, Z-stack images are collected, and a multispectral image data set is generated. The five probes are mixed and incubated at one time through a synchronous multiple labeling process, so that the operation time is remarkably shortened, and the risk of cell injury caused by multiple times of centrifugation is reduced; z-stack full-automatic scanning is combined with three-dimensional image acquisition, the capturing capability of weak fluorescence signals is improved through multi-focal plane fusion, and information loss caused by cell thickness or position offset in traditional two-dimensional imaging is overcome.

The invention relates to peptide-based non-protein load delivery. Methods, compositions, kits and synthetic peptide shuttle agents related to transduction of protein and / or non-protein loads are described. The methods generally include contacting a target eukaryotic cell with a non-protein load and a synthetic peptide shuttle at a concentration sufficient to increase the transduction efficiency of the non-protein load compared to the absence of the synthetic peptide shuttle. The non-protein load may be a drug for the treatment of disease, such as a small molecule drug. The invention also describes novel synthetic peptide shuttles having transduction activity on protein and / or non-protein loads, as well as the use of propidium iodide or other membrane impermeable fluorescent DNA intercalators as alternative loads for selecting multifunctional synthetic peptide shuttles having transduction activity on both protein and non-protein loads.

One objective is to provide a means for intracellular delivery of non-protein cargo. [Solution] Methods, compositions, kits, and synthetic peptide shuttles relating to the transduction of protein cargoes and / or non-protein cargoes are described herein. The methods generally include contacting target eukaryotic cells with a synthetic peptide shuttle at a concentration sufficient to increase the transduction efficiency of the non-protein cargo compared to the absence of the non-protein cargo and the synthetic peptide shuttle. In embodiments, the non-protein cargo may be a drug, such as a small molecule drug for treating a disease. In other embodiments, novel synthetic peptide shuttles having transduction activity for protein cargoes and / or non-protein cargoes are described, and further, the use of propidium iodide or other membrane-impermeable fluorescent DNA insertion agents as surrogate cargoes for selecting a versatile synthetic peptide shuttle having transduction activity for both protein and non-protein cargoes is described.

This invention relates to the field of fecal genomics kit technology, and particularly to a safe, rapid, and high-throughput kit for extracting fecal genomes and its usage method. The kit includes a sample preservation solution, magnetic beads, a lysis buffer, a washing buffer 1, a washing buffer 2, and an elution buffer. The sample preservation solution is composed of guanidine isothiocyanate, sodium citrate, Triton X-100, Tween 20, propidium iodide, and purified water. The magnetic beads are hydroxyl magnetic beads. The lysis buffer is composed of guanidine hydrochloride, Tris base, Tris hydrochloric acid, Triton X-100, isopropanol, and purified water. Washing buffer 1 is composed of guanidine hydrochloride solution and isopropanol. Washing buffer 2 is composed of anhydrous ethanol and purified water. This kit can easily extract the genome from fecal samples, is simple to operate, safe and non-toxic, and can extract multiple samples at once, enabling rapid diagnosis and filling the gap in the current market for automated high-throughput kits for extracting genomes from fecal samples.

Described herein are methods, compositions, kits and synthetic peptide shuttle agents relating to the transduction of proteinaceous and / or non-proteinaceous cargoes. The method generally comprises contacting target eukaryotic cells with a non-proteinaceous cargo and a concentration of a synthetic peptide shuttle agent sufficient to increase the transduction efficiency of the non-proteinaceous cargo, as compared to in the absence 5 of said synthetic peptide shuttle agent. In embodiments, the non-proteinaceous cargo may be a drug, such as a small molecule drug, for treating a disease. In other embodiments, novel synthetic peptide shuttle agents having transduction activity for proteinaceous and / or non-proteinaceous cargoes are described, as well as the use of propidium iodide or other membrane-impermeable fluorescent DNA intercalating agent as a surrogate cargo for selecting versatile synthetic peptide shuttle agents having transduction activity for both proteinaceous and non-10 proteinaceous cargoes.

The invention belongs to the field of microbe counting, and particularly relates to a dead and viable bacteria absolute numerical analysis method based on laser confocal fluorescence space analysis. According to the present invention, the survival state of the bacterial population is evaluated by monitoring the integrity of the cell membrane through the LIVE / DEAD BACLIGHT 1 KIT reagent (LIVE / DEADBacterium Viability Kits); the kit adopts a two-color fluorescence detection technology, and can be used for detecting viable bacteria of various bacteria genus. When the cell membrane is damaged to cause bacterial death or endangered, the cell membrane and the propidium iodide present red fluorescence or orange fluorescence (co-dyeing); and viable bacteria with a complete cell membrane and the SYTO9 dye present green fluorescence. The counting method is convenient and fast, and can accurately distinguish dead and viable bacteria.

The application discloses application of 2-ketobutyric acid, and finds that the 2-ketobutyric acid can obviously see the bacteriostatic circle on an aspergillus flavus plate at 2 mg. After the aspergillus flavus is added with 2-ketobutyric acid at 2 mg / mL, and after 24 and 48 hours of culture, the 2-ketobutyric acid can effectively achieve a bacteriostatic rate of more than 90%. Iodine propidium (PI) staining shows that the 2-ketobutyric acid treatment has damage to a fungal cell membrane. Transcriptome analysis shows that the 2-ketobutyric acid can down-regulate gene expression of aspergillus flavus biosynthesis. HPLC analysis can also show that after the aspergillus flavus is treated by the 2-ketobutyric acid, aspergillus flavus is obviously decreased relative to a control group.

The invention provides an organoid survival rate rapid screening method based on triple fluorescent staining, which is characterized by comprising the following steps: (1) organoid preparation: mechanically separated organoid units are washed and centrifuged to ensure that the size is 1-2mm; (2) triple fluorescent staining: adding a staining buffer solution containing calcein AM, propidium iodide (PI) and Hoechst33342 into the organoid, incubating at 37 DEG C in a dark place for 20-30 minutes, and washing to remove residual dye; (3) preparing a slide: mixing the anti-quenching mounting medium with the organoids, and preparing the slide in combination with a spacer; (4) fluorescence imaging: acquiring three fluorescence channel images under the same visual field by adopting a standard wide-field fluorescence microscope; and (5) semi-quantitative analysis: defining a region of interest through ImageJ / Fiji software, and measuring the integral density of each channel. The scheme provided by the invention can be directly applied to scenes such as organoid culture condition optimization, drug screening, treatment response evaluation and the like, drug-resistant subcloning can be identified, and technical support is provided for precise medical treatment.

The invention relates to the field of microorganisms, and provides a polysialic acid high-producing strain as well as a rapid screening method and application thereof. The screening method comprises the following steps: firstly carrying out primary screening on Escherichia coli mutant colonies through propidium iodide fluorescence color development, then carrying out negative screening by using a rifampicin-containing flat plate, inoculating the obtained target colonies to a high-flux porous plate, carrying out micro-fermentation secondary screening, and finally carrying out performance verification and confirmation by adopting shake flask fermentation. According to the screening method, the cell membrane permeability increasing strains are accurately and directionally screened, so that the screening efficiency of the polysialic acid high-yield mutant strains is remarkably improved. Through the implementation of the method, a polysialic acid high-yield strain is successfully screened, the strain is Escherichia coli, the strain is preserved in the China General Microbiological Culture Collection Center on May 19, 2025, and the preservation number is CGMCC NO.34585. The polysialic acid high-yield strain can be used for producing polysialic acid. The yield of polysialic acid of the strain in a 50L fermentation tank can reach 27.13 g / L.

This invention discloses a universal method for preparing nuclear suspensions suitable for flow cytometry of Rosa species, belonging to the field of plant biotechnology. The method uses WPB dissociation buffer and follows a standardized procedure to process Rosa leaves in different storage states through sample dissociation, filtration, staining, and incubation steps: leaf tissue is dissociated using WPB dissociation buffer pre-cooled to 4°C, allowed to stand on ice, filtered through a 40µm cell filter, and brought to volume. Propidium iodide and ribonuclease A are added for staining and incubation before flow cytometry analysis. This invention is directly applicable to Rosa leaves in three storage states: fresh, silica gel dried, and -80°C frozen. It is simple to operate, highly versatile, and the prepared nuclear suspension yields high-quality peak histograms with low coefficient of variation when analyzed by flow cytometry, providing an efficient and standardized technical solution for large-scale ploidy analysis and genome size determination of Rosa species.

This invention relates to the field of parasite egg quantity detection technology, specifically to a method and system for determining the number of parasite eggs in pet feces. The method involves pre-treating a fecal sample by mixing and shaking it with a compound releasing agent; collecting the egg-enriched solution through multi-stage filtration and backwashing; purifying the solution using a double-layer density gradient medium at specific speeds and times to form an egg-enriched layer; adding fluorescein diacetate and propidium iodide for active staining; collecting the stained egg layer at a flow rate of 0.5 ml / min; injecting the test suspension into a counting chamber; acquiring color images under a fluorescence microscope; and using a computer for color separation, target identification, deduplication of overlapping areas, and automatic counting to obtain the number of live and dead eggs and calculate the number of eggs per gram of feces. This method improves the egg recovery rate, simplifies the operation, enhances resistance to interference from impurities, and accurately distinguishes between live and dead eggs, making it suitable for the precise quantitative detection of parasite eggs in pet feces.