| Description | Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its asymmetric Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its asymmetric distribution across the phospholipid bilayer and is translocated to the extracellular membrane leaflet marking cells as targets of phagocytosis. Once on the outer surface of the membrane, PS can be detected by fluorescently labeled Annexin V in a calcium-dependent manner. In early-stage apoptosis, the plasma membrane excludes viability dyes such as propidium iodide (PI), 7-AAD. These cells will stain with Annexin V but not a viability dye, thus distinguishing cells in early apoptosis. However, in late stage apoptosis, the cell membrane loses integrity thereby allowing Annexin V to also access PS in the interior of the cell. A viability dye can be used to resolve these late-stage apoptotic and necrotic cells (Annexin V, viability dye-positive) from the early-stage apoptotic cells (Annexin V positive, viability dye-negative). This kit is suitable for the identification and enumeration of dead cells, such as apoptotic or necrotic cells, by flow cytometry.A1372287Components20T50T100TStorageQuantity Per TestA1372287A10X Annexin V Binding Buffer5 mL10 mL20 mL2-8℃200 µL per 0.5–1.0 × 10⁵ cells.A1372287BAnnexin V (APC)100 µL250 µL500 µL2-8℃. Store in the dark.5 µL per 0.5–1.0 × 10⁵ cells.A1372287CPropidium iodide Staining Solution (PI)100 µL250 µL500 µL2-8℃. Store in the dark.2 µL per 0.5–1.0 × 10⁵ cells.Note: The recommended number of cells to stain per test is 0.5–1.0 × 10⁵ cells.Instruction for use1. Dilute 10X Binding Buffer to 1X using distilled water (1 mL 10X Binding Buffer + 9 mL ddH2O).2. Wash cells twice with cold PBS and then resuspend the desired amount of cells in Annexin V Binding Buffer at a concentration of 0.5–1.0×10⁶/mL.3. Add 5 µl of FITC Annexin V and 2 µl PI to 100 µL of the cell suspension4. Gently vortex the cells and incubate for 10 min at RT (25°C) in the dark.5. Add 100 µl of 1X Binding Buffer to each assay. Analyze by flow cytometry within 1 hr... Read More | Inquire | The Endo F Multi-Kit will deglycosylate N-linked glycans in both native and denatured conditions. Each enzyme has a distinct specificity for N-linked glycan release. One can choose to use the three enzymes in combination to completely remove all N-linked glycans present on a glycoprotein or peptide,The Endo F Multi-Kit will deglycosylate N-linked glycans in both native and denatured conditions. Each enzyme has a distinct specificity for N-linked glycan release. One can choose to use the three enzymes in combination to completely remove all N-linked glycans present on a glycoprotein or peptide, or to use each enzyme independently and thereby determine the type of N-glycans present.Product DescriptionThe Endo F Multi-kit is recommended to deglycosylate native proteins that are resistant to PNGase F cleavage under non-denatured conditions due to the glycan location within the protein’s three-dimensional structure, as these enzymes are known to be less sensitive to protein conformation.Each of the enzymes has a different N-linked glycan specificity:Endoglycosidase F1 cleaves high mannose and some hybrid type N-glycansEndoglycosidase F2 releases biantennary and high mannose glycans (at a 40X reduced rate)Endoglycosidase F3 will release triantennarry and fucosylated biantennary N-glycansContents1 vial: Endo F1- 20 µl (0.3 U)20 mM Tris-HCl pH 7.51 vial: Endo F2- 20 µl (0.1 U)10 mM sodium acetate, 25 mM NaCl, pH 4.51 vial: Endo F3- 20 µl (0.1 U)20 mM Tris-HCl pH 7.51 vial: 5x Reaction Buffer - 400 µl250 mM sodium acetate, pH4.51 vial: 5x Reaction Buffer - 400 µl250 mM sodium phosphate, pH5.5Specific ActivityDefined as the amount of enzyme required to catalyze the release of N-linked oligosaccharides from 1 micro-mole of denatured Ribonuclease B (Endo F1) or porcine fibrinogen peptides (Endo F2/F3) in 1 minute at 37°C, pH 5.5 (PH 4.5 for Endo F3). Cleavage is monitored by SDS-PAGE.FormulationThe enzymes are provided as a sterile-filtered solution.StabilitySeveral days exposure to ambient temperatures will not reduce activity. Stable at least 12 months when stored properly.SpecificityEndo F1 cleaves Asparagine-linked (N-linked) high mannose or hybrid oligosaccharides. Endo F2 cleaves N-linked biantennary oligosaccharides and high mannose (at a 40X reduced rate). Endo F3 cleaves free or N-linked fucosylated biantennary or triantennary oligosaccharides,as well as triamannosylchitobiose core structures. These enzymes cleave between the two N-acetylglucosamine residues in the diacetylchitobiose core of the oligosaccharide, generating a truncated sugar molecule with one N-acetylglucosamine residue remaining on the asparagine. The recombinant version is not glycosylated, which may result in properties differing from the native protein.Quality & PurityEndo F1, Endo F2, and Endo F3 are tested for contaminating protease as follows: 10 µg of denatured BSA is incubated at 37°C for 24 hours with 2 µl of enzyme. SDS-PAGE analysis of the treated BSA shows no evidence of degradation. The absence of exoglycosidase contaminants is confirmed by extended incubations with the corresponding pNP-glycosides. Directions for use 1. Add up to 200 µg of glycoprotein to an Eppendorf tube. Adjust to 34 µl final volume with de-ionized water. 2. Add 10 µl Endo F2 &F3 5x Reaction Buffer, 250 mM sodium acetate pH 4.5. Use Endo F1 buffer, 250 mM sodium phosphate pH 5.5 if you are using the Endo F1 enzyme alone. 4. Add 2.0 µl of each enzyme to the reaction. Incubate 3 hours at 37°C. Monitor cleavage by SDS-PAGE. Applications– Deglycosylation of native proteins resistant to PNGase F cleavage– Determination of glycan type (high mannose, biantennary, tri/tetrantennary)– Deglycosylating proteins which normally precipitate when deglycosylating– X-Ray CrystallographyThese three enzymes cleave asparagine-linked (N-linked) oligosaccharides between the two GlcNAc residues in the core of the oligosaccharide, generating a truncated sugar molecule with one N-acetylglucosamine residue remaining on the asparagine, enhancing the solubility of the protein. In contrast, PNGase F removes the oligosaccharide intact... Read More | DescriptionGreen LED Array for Photo KitAlysis high-throughput screening platform. For use with Photo KitAlysis Starter Kit (Z742612). User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsFeatures:Designed and tested by synthetic chemists.Controller provides repeatableDescriptionGreen LED Array for Photo KitAlysis high-throughput screening platform. For use with Photo KitAlysis Starter Kit (Z742612). User guide is provided in the below hyperlink.Photo KitAlysis Operating InstructionsFeatures:Designed and tested by synthetic chemists.Controller provides repeatable milliamp selection for photon intensity (sold seperately)527 nm wavelength0-30 mA variable LED outputNon-magnetic LED baseChemically resistant LED coverPTFE coated cablingPhoto Kitalysis Starter Kitrequired for operation (sold separately). Best when used withKitAlysis Benchtop Inertion Box(sold separately)... Read More | Component Description T665563Component50 TStorageApplicationT665563AVNTR3820 1 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563BVNTR41201 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563CVNTR32321 mL-20℃. Avoid freeze/thaw Component Description T665563Component50 TStorageApplicationT665563AVNTR3820 1 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563BVNTR41201 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563CVNTR32321 mL-20℃. Avoid freeze/thaw cycle.High resolution 3-lite VNTR detectionT665563DMarkerⅠ300 µL-20℃. Avoid freeze/thaw cycle.DNA Molecular Weight Standard IT665563EMarkerⅡ250 µL-20℃. Avoid freeze/thaw cycle.DNA Molecular Weight Standard IIProduct IntroductionThis kit is a genotyping product for human Mycobacterium tuberculosis based on the latest research progress in molecular epidemiology1) and optimized by process. It utilizes variable-number tandem repeats (VNTR) polymorphisms in the Mycobacterium tuberculosis genome for genotyping to differentiate clinical strains, and is a powerful tool for studying the molecular epidemiology of Mycobacterium tuberculosis and monitoring the status of tuberculosis transmission. Compared with other existing Mycobacterium tuberculosis VNTR typing systems based on the VNTR principle, this typing system has a stronger ability to discriminate strains prevalent in China1,2,3), and is therefore particularly suitable for the needs of Chinese users.By carefully optimizing the primer sequences of each PCR reaction and the composition of the premixed reaction solution, this product has a strong anti-interference power. Compared with the user's own reagents, this product significantly improves the signal intensity of specific bands and reduces the appearance of non-specific bands when using crude templates (boiling bacterial solution), which makes the experimental operation easier and quicker, and at the same time, improves the success rate of the test. The premixed reaction solution is chemically stable and can effectively withstand repeated freezing and thawing (10 times) and a longer period of time (one week) at room temperature, which is better adapted to the user's need for flexibility in the detection work.This kit is a companion product to the TB Genotyping Kit VNTR-9. For samples identified as clustered or identical strains by the VNTR-9 kit, this product can be used for finer further typing identification if necessary. The three high-resolution detection sites VNTR3820, VNTR4120 and VNTR3232 in this product can be used in combination with the nine detection sites in the VNTR-9 to increase the resolution index (Hunter-Gaston index (HGI) to 0.9931).References1) Luo T et al. Development of a hierarchical variable-number tandem repeat typing scheme for Mycobacterium tuberculosis in China. PLoS One. 2014 Feb 25. 9(2)2)Sun G et al. Discriminatory potential of a novel set of Variable Number of Tandem Repeats for genotyping Mycobacterium marinum. Vet Microbiol. 2011 Aug Vet Microbiol. 2011 Aug 26;152(1-2)3) Zhang L et al. Highly polymorphic variable-number tandem repeats loci for differentiating Beijing genotype strains of Mycobacterium tuberculosis in Shanghai, China. FEMS Microbiol Lett. 2008 May;282(1):22-31.matters needing attention1.This product is a companion to the TB genotyping kit VNTR-9. The strains to be tested should be tested by VNTR-9 typing test first, and then use this product for testing. And the results of this product should be integrated and analyzed with the results of VNTR-9.2.To avoid contamination, it is recommended that the preparation of the organisms be done within a different location than the preparation of the PCR Mix and that different pipettes be used.3.Care should be taken at all stages of sample DNA collection, extraction and amplification to ensure proper labeling and to prevent cross-contamination between different samples.4.Commonly used reagents and consumables need to be autoclaved before experimentation.5.Each tube of PCR Mix contains different primers and cannot be mixed. It can be dispensed into different amounts at once according to the experimental needs to avoid repeated freezing and thawing.6.To avoid splashing the reaction solution when opening the reaction tube, centrifuge briefly before opening the cap and collect the liquid at the bottom of the tube. In case of accidental splashing on gloves or table, change gloves immediately and wipe the table with 75% alcohol or dilute acid.7.Be careful not to cross-contaminate the PCR Mix when aspirating, and it is recommended that the pipette tip be wiped with 75% alcohol 2 times before taking Mix each time.8.Pre-experiment preparation: 1×TE buffer (PH=8.0), 0.5×TBE buffer, agarose, ethidium bromide (EB), normal PCR instrument, DNA electrophoresis equipment and gel imager, 0.2 ml PCR reaction tubes, octuplex or 96-well PCR tubes, pipettes of different sizes: 0.5-10 µl and 20-200 µl.Operation steps1. DNA template preparation:1.1. scrape a small amount (1-2 inoculation loops) of sample from solid medium, resuspend in 100ul TE and inactivate at 80°C for 30 minutes.1.2. The inactivated strain was taken out of the P3 laboratory as follows:Boil at 100°C for 10 minutes (be careful to avoid bursting the cap of the EP tube during boiling to avoid letting water into the tube), place immediately on ice for 2 minutes, centrifuge at 12,000 rpm (~13,400 × g) for 10 minutes, take the supernatant and place in another sterile EP tube, label it, and store at -20°C.2. Testing procedures:2.1. Remove the TB Genotyping Kit HV-3, allow the liquid to equilibrate to room temperature, mix by shaking slightly 3-4 times, and then centrifuge at 12,000 rpm (~13,400 x g) for 5 seconds to allow the capped liquid to fall back into the tube.2.2.Three-locus VNTR typing: strains with identical results at 12 loci need to be further VNTR typed, i.e., the following four loci are added for comparison.1）PCR amplification: the reaction system was 20 µl. 19 µl of PCR Mix of VNTR3820, VNTR4120, and VNTR3232 were added to each PCR tube, 1 µl of DNA template was added, and mixed well.2）Amplification conditions:3) Gel preparation and electrophoresis:a: Notes:Important! Positive (H37Rv strain DNA) and negative controls (deionized water) need to be set up for each experiment.Key! This experiment is based on agarose gel electrophoresis to interpret the genotype of VNTR locus, therefore, in order to make the results accurate, it is necessary to follow the unified standard operation in this step of electrophoresis, and the following points should be noted:a-1: The comb used for glue making is 18 holes.a-2: The two wells on the left and right sides of the gel were discarded due to the tendency to distort the bands during electrophoresis, affecting the interpretation of the results, or a negative control was spotted in one of the wells. The remaining 16 wells were divided into 12 samples, 3 DNA Markers and 1 positive control. The order of spotting was "1, 2, M, 3, 4, 5, 6, M, 7, 8, 9, 10, M, 11, 12, H37Rv", the numbers represent samples, and M represents DNA Marker.a-3: When PCR amplification products are subjected to the first electrophoresis and Marker I is used, the gel concentration is 1%, the voltage is 150 V, and the time is 100-120 min.a-4: If the amplification product fragment is too large (>1000bp) and needs to be electrophoresed again and Marker II is used, the gel concentration is 0.8%, the voltage is 150V and the time is 150 minutes.b: Gluing as well as the electrophoresis process:PCR amplification products were electrophoresed using a 1% agarose gel.To prepare 1% agarose gel, 12×12 cm gel tray was used to make the gel, each gel was 80 ml.b-1: Weigh 0.8g of agarose, add 80ml of 0.5×TBE, weigh it on the balance and put it into the microwave oven, heat it on high for 2-3 minutes to make the agarose dissolve completely, shake it well, and observe it as a homogeneous and transparent solution without particles, then weigh it again on the balance and make up the appropriate amount of double-distilled water to keep the concentration of the gum unaffected.b-2: When the melted gel was cooled to about 55°C add 4 µl of ethidium bromide (10ug/ml) and gently swirl to mix well. The gel was made with an 18-tooth comb and the warm gel was poured into a 12 × 12 cm gel tray.b-3: Allow the gel to completely set (40 minutes at room temperature), carefully pull out the comb, remove the tray, and place it in the electrophoresis tank. Add 0.5× TBE buffer to the electrophoresis tank, not exceeding the gel surface by 1-2mm.b-4: Sample electrophoresis: add 12 samples to each gel (the topmost wells are not sampled), add 3-5µl PCR products to each well, and at the same time add three 5µl DNA MarkerⅠ to each gel. The voltage is 150V and the electrophoresis time is 100-120 minutes. This step is the key to the accuracy of the final readings of each point, and needs to be operated uniformly according to this standard.b-5: Some loci have amplification products greater than 1000bp in clinical strains, and these amplification products were then electrophoresed using 0.8% agarose gel, with DNA Marker II added as a control for the band size, voltage 150V, electrophoresis time 150 minutes.4) Results display:5) Analysis of results:a. If the genotypes of the three highly variable loci are also the same in different strains, they can be identified as clustered strains;b. If the high variant readings are highly similar, i.e., only 1-2 high variant sites are different, they need to be combined with epidemiologic data to identify if they are clustered strains;c. If all 3 high variant loci are genotypically discordant, identify as a single strain.Appendix 1: Rules for reading VNTR lociAppendix 2: VNTR locus repeat unit readout table... Read More |