| Description | CNTLN Human Pre-designed siRNA Set A contains three designed siRNAs for CNTLN gene (Human), as well as a negative control, a positive control, and a FAM-labeled negative control. Components CNTLN siRNA-1: 5 nmol (HPLC) CNTLN siRNA-2: 5 nmol (HPLC) CNTLN siRNA-3: 5 nmol (HPLC) siRNA Negative Control:CNTLN Human Pre-designed siRNA Set A contains three designed siRNAs for CNTLN gene (Human), as well as a negative control, a positive control, and a FAM-labeled negative control. Components CNTLN siRNA-1: 5 nmol (HPLC) CNTLN siRNA-2: 5 nmol (HPLC) CNTLN siRNA-3: 5 nmol (HPLC) siRNA Negative Control: 5 nmol (HPLC) FAM-labeled siRNA Negative Control: 5 nmol (HPLC) GAPDH siRNA Positive Control:5 nmol (HPLC)... Read More | Amine-Reactive probe which passively diffuse into cells and it is nonfluorescent until the acetate groups are cleaved by intracellular esterases to yield the highly fluorescent, amine-reactive fluorophore. Upon reaction with amine-containing residues of intracellular proteins, these probes form dye Amine-Reactive probe which passively diffuse into cells and it is nonfluorescent until the acetate groups are cleaved by intracellular esterases to yield the highly fluorescent, amine-reactive fluorophore. Upon reaction with amine-containing residues of intracellular proteins, these probes form dye protein adducts that are well retained in cells as they move and divide during embryonic development.A Non-fluorescent cell permeant amine-reactive probe for long term tracing of cell... Read More | Protein Purity>95% by SDS-PAGEExtinction Coeff.A276 nm = 0.456 at 1.0 mg/mLMolecular Weight8,759 Da (single chain)General DescriptionNatural human C4a is prepared by cleavage of human C4 protein by human C1s. It is produced during activation of both the classical and lectin pathways of complementProtein Purity>95% by SDS-PAGEExtinction Coeff.A276 nm = 0.456 at 1.0 mg/mLMolecular Weight8,759 Da (single chain)General DescriptionNatural human C4a is prepared by cleavage of human C4 protein by human C1s. It is produced during activation of both the classical and lectin pathways of complement. C4a is a member of the anaphylatoxin family of three proteins (C3a, C4a and C5a) produced by the activation of complement (Hugli, T.E. et al. (1981)). It is an unglycosylated polypeptidecontaining 77 amino acids with a molecular mass of 8,759 daltons. Many of the biological functions of C4a are similar to those of C3a, but the specific activities are far below those of C3a. C4a activity is so low, in fact, that it was initially thought to be inactive. These measured activities include inducing muscle contraction in the guinea pig ileum test (spasmogenic activity), desensitization of muscle to C3a stimulation suggesting that the same receptor for both C3a and C4a is involved (tachyphylactic activity) and inducing vascular permeability in human skin (Gorski J.P. et al. (1979)). C4a does not show tachyphylactic activity against C5a or chemotactic activity. Removal of the C-terminal arginine by serum carboxypeptidase N destroys all these activities (Meuller-Ortiz, S.L., et al. (2009)). C4a appears to act through the C3a receptor (C3aR) which is a G-protein coupled receptor found widely distributed on peripheral tissues, lymphoid cells (neutrohphils, monocyes, and eosinophils) and in the central nervous system (astrocytes, neurons and glial cells) (Law, S.K.A. and Reid, K.B.M. (1995)). Physical Characteristics & StructureMolecular weight: 8,759 calculated molecular mass. Observed mass (MALDI-TOF) is 8,762 + 9 mass units. pI = 9.0 to 9.5 (Gorski, J.P. et al. (1981))Amino acid sequence (77 amino acids): NVNFQKAINE KLGQYASPTA KRCCQDGVTR LPMMRSCEQR AARVQQPDCR EPFLSCCQFA ESLRKKSRDK GQAGLQRC4a is thought to be structurally very similar to C3a and C5a to which it is homologous. Thus its 3D structure is probably similar to the X-ray-derived crystal structureof C3a (Huber, R. et al. (1980)) and the NMR derived structure of C3a: Nettesheim, D.G. et al. (1988); Murray, I. et al. (1999).FunctionSee General Description above. C4a exhibits much weaker biological activities than C3a and C5a. Its activity in inducing erythema and edema in human skin is 25,000-fold weaker than that of C5a and 100-fold weaker than C3a per nanomole. The spasmogenic activity of C4a is 2000-fold weaker than C5a and 100-fold weaker than that of C3a. Due to these differences the role of C4a in these responses in vivo is thought to be negligible.AssaysTwo well established assays for C4a and C3a functional activities include induction of contraction in the guinea pig ileum and the permeation of a dye such as trypan blue from the vasculature into skin. The anaphylatoxins also induce mast cell degranulation, (measured as histamine release), platelet aggregation, IL-1 release from monocytes and the release of prostaglandins and leukotrienes from many cells and tissues. The other assays used for C3a (Dodds, A.W. and Sim, R.B. (1997)) should also respond to C4a, but few reports have described utilizing these assays with C4a. ELISA kits for the assay of C4a levels (or more correctly C4a desArg levels) in blood and other fluids are sold by several companies. These measurements are useful for detecting complement activation in vivo, but the interpretation of their meaning is complicated by the fact that clearance of the anaphylatoxins is rapid. In vivoFreshly drawn normal human serum contains significant levels of all three anaphylatoxins. Although these may represent the resting concentration in vivo it is difficult to draw or store blood without some complement activation so a true in vivo concentration is difficult to determine. The presence of EDTA and Futhan in the collection tubes can minimize this background (Pfeifer, P.H. et al. (1999)). Full activation of all C4 in blood (600µg/mL) would result in ~3,400 nM C4a (~30 µg/mL). Due to the low biological activity of C4a it could require activation of most of the C4 in a small region to achieve the micromolar C4a concentrations necessary to elicit a response.RegulationC4a levels are regulated by three processes: formation, inactivation and clearance. There are two enzymes that cleave C4 and release C4a: C1s and MASP-2. C4a is “inactivated” by removal of its C-terminal arginine amino acid. The product C4a desArg (or C4a without the C-terminal arginine) is produced by the action of the plasma enzyme carboxypeptidase N (Mueller-Ortiz S.L. et al. (2009)). The inactivation is rapid and most C4a is converted to C4a desArg within minutes of its formation. Inactivated C4a lack measurable biological activity. Because of the large number of cells bearing C3a/C4areceptors (endothelial, immune, smooth muscle, neuronal, etc.) the capture, internalization and digestion of C4a and C4a desArg probably results in its removal from circulation.DeficienciesA deficiency of C4 or a deficiency of all of the enzymes that cleave C4 to generate C4a could result in the absence of C4a. There are no known complete deficiencies of all ofthe C4 cleaving enzymes. Examples of C4 deficient humans and mice exist (Wessels, M.R. et al. (1995)), but the degree to which pathologies associated with C4 deficiency are due to the lack of C4 or the absence of C4a is unclear. DiseasesThere are no known diseases connected to C4a or C4a desArg. Precautions/Toxicity/HazardsThe source of C4a is human serum, therefore appropriate precautions must be observed even though the source was shown by certified tests to be negative for HBsAg, HTLV-I/II, STS, and for antibodies to HCV, HIV-1 and HIV-II.Injection can cause anaphylatic shock which is a generalized circulatory collapse similar to that caused by an allergic reaction.Hazard Code: B WGK Germany 3... Read More | ProductsThis product is a high purity genomic DNA extract from 293T cells, agarose gel (0.7%) electrophoresis showed that the size of the DNA extract is more than 15Kb, and basically no degradation, the product is ultimately preserved in TE Buffer, which can be widely used in molecular biology ProductsThis product is a high purity genomic DNA extract from 293T cells, agarose gel (0.7%) electrophoresis showed that the size of the DNA extract is more than 15Kb, and basically no degradation, the product is ultimately preserved in TE Buffer, which can be widely used in molecular biology experiments, such as PCR, enzyme digestion, hybridization, microarray analysis, and other molecular biology experiments.The product was quantified using NanoDrop One at a concentration of 200 ng/µL.Preparation and precautions before useLong-term storage at -20˚C is recommended. Before use, the bottle should be removed from the refrigerator and equilibrated to room temperature and centrifuged before opening the cap for use. Samples should be restored to the sealed state as soon as possible after opening.How to use (take qPCR experiment as an example)1. Amplification template preparationThe samples to be detected were diluted with TE (10 mM Tris-Cl, pH 8.0,1 mM EDTA), and the concentration after dilution was as close as possible to the range of 0.05-10 ng/µL. The samples were placed on ice at 4°C and set aside.2. Standard dilution: according to the following table, firstly dilute Human DNA Standard 1 (100ng/uL) with TE to make 5 different concentrations of standards according to the table below. 10ng/µL of DNA Standard 1 (Std. 1) can be stored stably at -20℃ for 1 month; Std2-5 can only be used on the same day, and should be placed at 4℃ or on ice when not in use for the time being after preparation. When not used temporarily after preparation, it should be stored at 4℃ or on ice.styleCorresponding concentration (ng/µL)Minimum dilution volume (in µL)Std.11010 [100 ng/µL DNA Standard 1] + 90 TEStd.22.520 [Std. 1] +60 TEStd.30.62520 [Std. 2] +60 TEStd.40.1562520 [Std. 3] +60 TEStd.50.039062520 [Std. 4] +60 TE3. qPCR reaction system preparationThe cryopreserved reagents to be used were completely thawed and mixed by inversion several times before preparation, and then briefly centrifuged and prepared for use. 20 µL of the base reaction system was as follows.The base reaction system for 20 µL was as follows:reagents20µL reaction system2×qPCRMix10µLPrimerMixXµLProbeMixXµLTemplate4µLddH2OMake up to 20 µLNote: High Rox model: add 1 µL of 50×High Rox per 50 µL of reaction system; Low Rox model: add 1 µL of 50×High Rox per 500 µL of reaction system.Usually, better results can be obtained with a primer concentration of 0.2 µM, and 0.1-1.0 µM can be used as a reference for setting the range.The concentration of the probe used is related to the fluorescent quantitative PCR instrument used, the type of probe, and the type of fluorescent labeling substance, so please refer to the manual of the instrument or the specific requirements for the use of each fluorescent probe for the adjustment of the concentration during actual use.Prepare a sufficient amount of reaction system mixture as required. After the reaction system has been prepared and mixed thoroughly, add 16 µL per well to the reaction wells. Then add the prepared standard and diluted sample into the corresponding reaction wells, the volume of addition is 4µL/well. TE was added to the blank control tube, and the same amount of TE was added at 4 µL/well.It is recommended to use 20 µL for the reaction, if you need to perform a smaller system reaction, reduce the system components in equal proportion.4. qPCR reaction programThe following is an example of our GoldStar Probe Mixture reaction conditions, which should be improved and optimized according to the PCR product template, primer structure and target fragment size.movetemptimingcirculatepremutability95°C10min1denaturation95°C10sec55Annealing/Extension60°C30sec5Data analysis1. Standard curve productionThe standard curve was plotted with reference to the Excel sheet for data processing. The correlation coefficient R2 of the standard curve should not be lower than 0.98, and the slope should be between -3.1 and -3.6 when the Ct value is the vertical coordinate. If the parameters of the standard curve are unreasonable, it is recommended to repeat the experiment... Read More | BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L,BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L, the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature. Unlike egg-white avidin, which has a net positive charge at neutral pH and contains about 7% carbohydrate, streptavidin has almost no net charge at neutral pH, does not contain carbohydrate, and exhibits lower non-specific background. Streptavidin conjugates are widely used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids and other molecules. This FITC-streptavidin conjugate was prepared by highly purified Streptavidin and free FITC was removed. Streptavidin (FITC) is a useful second-step reagent for the indirect immunofluorescent staining of cells in combination with biotinylated primary antibodies for flow cytometric analysis. Excitation at 488nm light leads to a fluorescence emission maximum of 520 nm.Recommended Usage：Every lot of Streptavidin-FITC is tested by flow cytometry using biotinylated primary antibodies. From this testing it is recommended that between 0.02 and 0.25 µg of streptavidin be used per 106 cells in a 100 µl staining volume... Read More |