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CY3/CY5.5/CY7.5 NHS ester标记氨基分子方法 NG体育是一家以化学、生物和材料科学等领域的科研用研发产品的制造贸易商，我们的产品在基础科学领域得到广泛的应用。客户包括大专院校科研院所的研究开发实验室以及制药、生物技术等具商业规模的企业。目前我们能提供超过几千种产品的库存，包装大小从克级到公斤级大包装规格，也包括部分半散装和散装产品，我们的库存品种每天都在增加。 重视质量是我们针对产品和服务关键的组成部分，通过质量赢得客户100%的满意和信赖是我们永远的追求,我们坚信质量是企业的生命。我们的质量管理体系遵照ISO9001标准建立，并通过的信息化管理得到了彻底的贯彻，保证了产品的每一个过程都得到控制，确保涉及产品质量的各业务流程标准化、制度化。 NG体育也是一个以服务为导向的公司。提供给客户的远不止产品本身，还包括现货库存、包装、应急反应、退换货、客户的技术支持等因素的100%客户满意度。我们建立了一支业务精炼、服务周到的客服队伍，把满足客户的需求作为我们的工作宗旨，服务渗透到售前、售中、售后，甚至延伸到产品本身之外，我们争取做到出售的不再是简单的产品，而是服务。 我们可以提供的活化羧基系列荧光染料包括： Cyanine3 NHS ester Cyanine5 NHS ester Cyanine5.5 NHS ester Cyanine7 NHS ester Cyanine7.5 NHS ester Cy3 NHS ester Cy5 NHS ester Cy5.5 NHS ester Cy7 NHS ester Cy7.5 NHS ester ICG NHS 其他的荧光染料欢迎来咨询： 标记方法说明如下： NHS (N-HydroxySuccinimide) esters and otheractivated esters (sulfo-NHS, sulfotetrafluorophenyl-STP) are reactive compoundssuitable for the modification of amino groups. NHS is most common type ofactivated esters.   Usual modifications are fluorescent labels,fluorescence quenchers, and other reporter groups. Alkyne and azido group can be attachedusing activated esters to adapt biomolecules to Click Chemistry.   Since amino groups are nearly alwayscontained in proteins and peptides, modification of these biopolymers is especially common. Otherexamples are amino-oligonucleotides, amino-modified DNA,and amino-containingsugars.   The reaction of NHS esters with amines isstrongly pH-dependent: at low pH, the amino group is protonated, and no modification takesplace. At higher-than-optimal pH, hydrolysis of NHS ester isquick, andmodification yield diminishes. Optimal pH value for modification is 8.3-8.5.   Water is most common solvent for thelabeling. If NHS ester is poorly soluble, it can be added as a solution in DMSO or DMF to a solution ofprotein in water, adjusted to pH 8.3-8.5. Note that DMFmust not contain amines(and thus should have no odor).   We recommend using the following generalprotocol for the labeling of biomolecules with NHS esters produced by Ruixibio. 1. Calculate required amount of NHS ester: NHS_ester_weight [mg] = 8 ×amino_compound_weight [mg] × NHS_ester_molar_weight [Da] / amino_compound_molar_weight [Da].   8 is molar excess of NHS ester. It isexperimental value for mono-labeling, suitable for many common proteins and peptides. However, insome cases using less or more NHS ester is required. It depends on protein structure, reagent,and solubility. Molar weight of Lumiprobe products can be found on corresponding product pages.   For example, to label 3 mg of BSA (molarweight 69300 Dalton) with Cy5 NHS ester (molar weight 616 Dalton), andobtainmaximum yield of mono-labeled product, one should use 8 × 3 mg × 616 Da / 69300Da = 0.21 mg of Cy5 dye NHS ester.   2. Determine volume of reaction mixture.The labeling can be performed on any scale from nanomols to dozens of grams. When the scaleis low, use minimal volume (10-20 uL). Higher concentrations (1-10 mg of amino-biomoleculeper mL of mixture) are optimal.   3. Dissolve NHS ester in 1/10 reactionvolume of DMF or DMSO. Amine-free DMF is preferred solvent. After the reaction, NHS ester canbe stored in solution for 1-2 months at -20ºC.   4. Dissolve biomolecule in 9/10 reactionvolume of buffer with pH 8.3-8.5.   0.1 M Sodium bicarbonate solution hasappropriate pH. Another alternative is 0.1 M phosphate buffer. Note pH is the most importantthing. Avoid using buffers containing amines (Tris can sometimes be used but not recommended).   When doing large-scale labeling (hundredsof milligrams of NHS ester), note that the mixture tends to acidify with time because ofhydrolysis of NHS ester. Monitor pH, or use more concentrated buffer then.   5. Add NHS ester solution to the solutionof biomolecule, and vortex well. Keep on ice overnight, or at room temperature during at least 4hours.   6. Purify the conjugate using appropriatemethod: gel-filtration for macromolecules is most universal. Precipitation and chromatographyis another alternative. Organic impurities (such as Nhydroxysuccinimide,NHSester, acid produced by hydrolysis) are almost always easily separated.Forproteins and nucleic acids, ethanol or acetone precipitation can be used.