重组长臂巯基核心链霉亲和素（r-las-cSA）

重组长臂巯基核心链霉亲和素

Recombinant Long-Arm Sulfhydryl Group Core Streptavidin | r-las-cSA

R767450-1mg

1mg

BioReagent

≥95%(SDS-PAGE)

分子量： 54.8kDa (tetramer), 13.7kDa (monomer) 储存缓冲液： Lyophilized from 20mM HEPES , Trehalose, TCEP, pH 7.0 复溶(Reconstitution)： Reconstitute in sterile distilled water. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriate buffered solutions. 链霉亲和素（Streptavidin，SA）是阿维丁链霉菌（Streptomyces avidinii）在生长过程中分泌的一种同型四聚体蛋白。同亲和素一样，一摩尔的链霉亲和素可以结合四摩尔的生物素，与生物素具有很高的亲和力。由于链霉亲和素不含糖基且等电点接近于中性，因此链霉亲和素在检测应用中具有比亲和素更低的非特异性结合水平。 该制品已被广泛应用于多种生物技术领域，诸如：包被免疫检测用微孔板，制备 SA 偶联酶制剂，SA 偶联荧光素、SA 偶联磁珠等，进而参与酶联免疫吸附和酶催化放大实验，免疫组化化学、生物分子纯化、生物传感器、生物纳米微球、预靶向制药研究和生物芯片被料等。 重组长臂巯基核心链霉亲和素与天然链霉亲和素相比，去除与活性无关的序列，仅保留与活性有关的核心序列，稳定性、溶解性等方面均优于天然链霉亲和素，同时和阿拉丁链霉亲和素系列产品 R767460比，在C端的半胱氨酸前插入了6个额外的柔性氨基酸，加长了C端巯基臂长度，可以让 SA 更好地定向与载体共价键合。(该重组长臂巯基核心链霉亲和素 pI：6.09) 来源： 大肠杆菌发酵工程菌株 使用方法： （仅供参考） 由于产品生产工艺中冻干环节会引入保护剂等，为减少您的实验误差，建议先通过内部检测 方法，产品中蛋白进行准确定量后，再进行后续实验，并按实际情况进行产品用量调整。建议优先选择紫外吸收法进行定量，方法如下： 将样品从低温条件下拿出后，平衡至室温，并擦去瓶外附着的冷凝水，小心打开瓶盖，防止干粉飞溅损失。用去离子水或缓冲液进行复溶，充分溶解后，稀释至合适浓度，小心移入比色皿中，以去离子水或缓冲液为空白对照，测定样品在 280 nm 处的吸光值（建议吸光值控制在 0.1-1.5区间内），将其代入以下公式计算蛋白质浓度： 式中：C：样品原液的蛋白质质量浓度（mg/mL） A280nm：蛋白质溶液在 280nm 处测得的吸光值 N：稀释倍数 E(0.1% at 280nm)：1 mg/mL 蛋白质的消光系数 例如将本产品冻干粉充分溶解并混匀后，取适量原液稀释 10 倍，测得其在 280 nm 处的吸光值为0.915，则原液的蛋白浓度为 10×0.915/3.05=3 mg/mL。 注意事项： 1. 重组长臂巯基核心链霉亲和素冻干粉易溶于水，溶解性可达 10 mg / mL 或更高； 2. 建议使用纯水溶解； 3. 如有未溶解物质，建议延长复溶时间。也可以通过离心或其他方式除去不溶物后，再用于后续实验，不会对总蛋白产生很大的影响。 4. 考虑到蛋白质特殊性，冻干粉建议现用现配，溶解后应避免反复冻融，如需多次使用，建议按需分装后冻存（-20°C）；避免在 4°C下长期存放。 M：蛋白质分子量标准 Lane 1：重组长臂巯基核心链霉亲和素单体 Lane 2：重组长臂巯基核心链霉亲和素四聚体 Source E. coli fermentation engineering strain Product introduction Streptavidin (SA) is a homologous tetramer protein secreted by Streptomyces avidinii during its growth. As with avidin, one mole of streptavidin can bind four moles of biotin, and biotin has a high affinity. Because streptavidin does not contain a sugar group and its isoelectric point is close to neutral, streptavidin has a lower non-specific binding level than avidin in detection applications. Compared with natural streptavidin, the recombinant long-brassicyl core streptavidin removes the sequence unrelated to activity and only retains the core sequence related to activity, which is superior to natural streptavidin in terms of stability and solubility. At the same time, compared with Newlong biostreptavidin series A09, 6 additional flexible amino acids are inserted in front of C-terminal cysteine. The lengthening of the C-terminal sulfhydryl arm can make SA more oriented to covalently bond with the carrier. (The recombinant long arm Streptavidin pI: 6.09). The product has been widely used in a variety of biotechnology fields, such as: Coated with microporous plates for immunoassay, preparation of SA coupled enzyme preparations, SA coupled fluorescein, SA coupled magnetic beads, etc., and then participate in enzyme-linked immunoadsorption and enzyme catalytic amplification experiments, immunohistochemistry, biomolecular purification, biosensors, biological nanospheres, pre-targeted pharmaceutical research and biochip materials. Method of use (for reference only) Due to the introduction of protective agents in the freeze-drying process of the product, in order to reduce your experimental error, it is recommended to first pass the internal detection method, and accurately quantify the protein in the product, and then conduct follow-up experiments, and adjust the product dosage according to the actual situation. It is recommended that UV absorption method be preferred for quantification, as follows: After taking the sample out of the low temperature condition, balance to room temperature, and wipe away the condensed water attached to the outside of the bottle, and carefully open the bottle cap to prevent the loss of dry powder splash. Redissolve with deionized water or buffer, after fully dissolved, dilute to a suitable concentration, and carefully move into the cuvea, using deionized water or buffer as a blank control, determine the absorbance value of the sample at 280 nm (it is recommended that the absorbance value be controlled within the range of 0.1-1.5), and substitute it into the following formula to calculate the protein concentration: C: Protein mass concentration of the sample stock solution (mg/mL) A280nm: The absorption value of the protein solution measured at 280nm N: dilution ratio E(0.1% at 280nm) : extinction coefficient of 1 mg/mL protein For example, after the freeze-dried powder of the product is fully dissolved and mixed, the appropriate amount of the stock solution is diluted 10 times, and the absorption value at 280 nm is 0.915, then the protein concentration of the stock solution is 10×0.915/3.05=3 mg/mL. Note 1. The freeze-dried powder is soluble in water, and its solubility can reach 10 mg/mL or higher; 2. It is recommended to use pure water to dissolve; 3. If there are undissolved substances, it is recommended to extend the re-dissolution time. The insoluble matter can also be removed by centrifugation or other means, and then used in subsequent experiments, and will not have a great impact on the total protein. 4. Considering the particularity of protein, freeze-dried powder is recommended to be used on the go. Repeated freeze-thawing should be avoided after dissolution. If it is needed for multiple uses, it is recommended to be frozen after packaging as required (-20°C); Avoid long-term storage at 4°C. M: Protein molecular weight standard Lane 1: Recombinant streptavidin monomer Lane 2: Recombinant streptavidin tetramer

Unconjugated