UltraBio™ Protein G Plus磁珠

P751578-1ml

1ml

阿拉丁研发生产的UltraBio™ Protein G Plus磁珠(UltraBio™ Protein G Plus Magnetic Beads)，也称Protein G免疫磁珠、Protein G免疫沉淀磁珠、SPG磁珠、蛋白G磁珠、蛋白G免疫磁珠或蛋白G免疫沉淀磁珠，是由优化改造的高质量的重组Protein G与纳米级氨基磁珠共价偶联而成。Protein G Plus磁珠与Protein G磁珠相比，特异性结合相应抗体的能力更强，相同磁珠用量情况下Protein G Plus磁珠能多结合约30-50%的抗体，主要用于免疫沉淀(Immunoprecipitation, IP)、免疫共沉淀(Co-IP)或染色质免疫沉淀(Chromatin Immunoprecipitation, Ch-IP)，也可以用于血清、细胞培养上清液或腹水等样品中抗体的纯化等。Protein G是C型或G型链球菌表达的免疫球蛋白结合蛋白；Protein A是一种发现于金黄色葡萄球菌的细胞壁表面蛋白，分子量为42kDa。Protein G和Protein A功能相似，能特异性地与哺乳动物免疫球蛋白(Immunoglobulin, Ig)结合，结合的部位通常为免疫球蛋白的Fc区，但有资料显示Protein A也会和人VH3家族的Fab区结合，而Protein G有时与Fab区也有一定结合。同时，两者对于不同的免疫球蛋白亚类的结合能力有所不同。适当重组改造的Protein A 、G与磁珠以一定的方式结合，可用于免疫沉淀或抗体的纯化。本磁珠使用的Protein G Plus在不改变Protein G基本性能的情况下，优化了Protein G同时结合3个IgG分子的空间位阻效应，特异性地结合相应抗体的能力更强，相同磁珠用量情况下Protein G Plus磁珠能多结合约30-50%的抗体。和Protein G磁珠相同，Protein G Plus磁珠适合于免疫沉淀human IgG1、IgG2、IgG3、IgG4，mouse IgG1、IgG2a、IgG2b、IgG3，rat IgG1、IgG2a、IgG2b、 IgG2c，以及rabbit、goat多克隆抗体，而Protein A磁珠适合于免疫沉淀human IgG1、IgG2、IgG4，mouse IgG2a、IgG2b及rabbit IgG等。下表是阿拉丁Protein A、Protein G、Protein A/G磁珠产品与人、小鼠、大鼠常见的免疫球蛋白亚类的结合能力及不同物种的总结合能力情况表。本产品中的重组Protein G Plus可与多数哺乳动物IgG的Fc端特异性结合，分子量约为25kDa。该重组Protein G Plus通过改造，仅保留了与IgG Fc端结合相关的氨基酸序列，去除了结合位点以外可能导致非特异性结合的序列，从而可以有效减少非特异性结合。本产品的每个Protein G Plus分子可以结合3个IgG分子。UltraBio™ Protein G Plus磁珠可以特异性地结合相应抗体，并可以借助磁力架等磁分离设备非常便捷地应用于抗体结合的目的蛋白或其蛋白复合物的免疫沉淀或抗体纯化等实验。本产品进行免疫沉淀的实验流程参考图1。图1. 阿拉丁的UltraBio™ Protein G Plus磁珠免疫沉淀流程图。本产品抗体结合特异性强、抗体结合量更高：传统的Protein G琼脂糖凝胶孔径大，容易产生非特异吸附，而本产品磁珠粒径小，不易产生非特异吸附。本产品每毫升磁珠悬浊液含约10mg磁珠，含有不少于0.6mg重组Protein G Plus，每个重组Protein G Plus具有3个Fc结合域，通常每毫升本磁珠悬浊液可结合不少于0.9mg人IgG，具体的最大结合量和抗体类型及目的蛋白等相关。每500微升样品，通常仅需使用10-20微升磁珠悬浊液，就可以高效地进行免疫沉淀实验。本产品结合抗体或抗体复合物的速度快：本产品所使用的纳米级磁珠(~200nm)具有超大比表面积，便于磁珠与抗体或抗体复合物的快速有效结合。通常10分钟内即可完成抗体或其复合物的吸附的过程，30分钟内完成目的蛋白免疫沉淀操作。缩短操作时间可以有效避免在长时间操作过程中目的蛋白的降解或变性，充分保证目的蛋白的活性。由于采用磁性分离，每次进行IP和Co-IP相比于琼脂糖凝胶可以节省40%的时间。本产品可选择多种洗脱方法：本产品根据抗体复合物中目的蛋白的结构、生物学功能及后续应用的要求等，可以使用多种洗脱方法，包括酸性溶液、SDS-PAGE上样缓冲液或竞争性多肽等洗脱液进行洗脱。本产品用于GFP-HA融合蛋白的免疫沉淀效果参考图2。图2. UltraBio™ Protein G Plus磁珠用于GFP-HA融合蛋白的免疫沉淀效果图。293T (人胚肾细胞)转染GFP-HA质粒36小时后，经Western及IP细胞裂解液裂解。样品1为Input，即全细胞裂解液；样品2、3和4都为本Protein G Plus磁珠免疫沉淀后的样品，其中样品2中使用的是正常的小鼠IgG (Normal Mouse IgG) 免疫沉淀后经SDS-PAGE蛋白上样缓冲液(1X) 洗脱后得到的样品，为阴性对照；样品3和4进行IP时使用的都是HA抗体，都使用SDS-PAGE蛋白上样缓冲液(1X)洗脱。其中样品3使用的是UltraBio™ Protein G Magnetic Beads ，样品4使用的是UltraBio™ Protein G Plus Magnetic Beads。图中可见UltraBio™ Protein G Plus磁珠比常规的UltraBio™ Protein G磁珠有更好的免疫沉淀效果。Western印迹成像由Imager 600化学发光成像系统完成。实际结果会因实验条件、检测仪器等的不同而存在差异，图中数据仅供参考。本产品使用便捷。本产品储存在特殊保护液中，不含甘油，可以通过磁性吸附实现快速高效的分离，无需离心操作。本产品的主要指标如下表：4℃保存，两年有效。长期不使用，可以 使用说明 ： 1.样品的制备。a.选择合适的裂解液，用于制备细胞或组织的裂解液。优先推荐选择阿拉丁生产的P0013 Western及IP细胞裂解液用于细胞或组织样品的裂解。根据特定的实验目的，如有必要，也可以使用阿拉丁生产的P0013B RIPA裂解液(强)、P0013C RIPA裂解液(中)或P0013D RIPA裂解液(弱)用于样品的制备。如果使用自行配制的或其它公司生产的裂解液，需要确保裂解液的pH为6-8。b.具体的细胞或组织样品裂解的制备步骤请参考裂解液的使用说明。制备好的裂解液上清宜置于冰上或4℃存放，随后即可用于免疫沉淀或免疫共沉淀、标签蛋白的纯化等操作。新鲜制备好的样品，建议尽量当天完成免疫沉淀等后续操作，但如果样品不能当天使用，也可以适当分装后-80℃冻存。2.Protein G Plus磁珠的准备。由于Protein G Plus磁珠储存在特殊保护液中，所以需要在加入样品前适当洗涤。a.用移液器轻轻吹打重悬Protein G Plus磁珠，按照每500μl样品10μl或20μl磁珠悬浊液，取适量Protein G Plus磁珠至一洁净离心管中，加入1X TBS 至最终体积为约0.5ml。说明：如果初始体积大于0.2ml，可以考虑先直接置于磁力架(FMS012/FMS024)上分离10秒，去除上清，然后再加入1X TBS 至最终体积为约0.5ml。b.用移液器轻轻吹打重悬Protein G Plus磁珠。置于磁力架(FMS012/FMS024)上分离10秒，去除上清。重复上述步骤两次。c.按照初始体积的量，用1X TBS 重悬Protein G Plus磁珠。3.抗体与Protein G Plus磁珠的结合。a.抗体的准备：按抗体使用说明中推荐的稀释比例用1X TBS稀释抗体，配制成抗体工作液；或将抗体配制成终浓度5-50μg/ml的抗体工作液。置于冰上备用。可选做：使用抗体种属相同的正常IgG配制相同稀释比或终浓度的正常IgG工作液，以用于去除非特异性结合或作为阴性对照。所谓种属相同的正常IgG是指，例如后续免疫沉淀时用的抗体是小鼠IgG，则在本步骤中可以用1X TBS稀释适量的normal mouse IgG以用于降低背景或作为阴性对照。b.抗体吸附：将步骤2准备好的Protein G Plus磁珠进行磁性分离，吸除上清，加入500μl抗体工作液或正常IgG工作液，重悬后在室温翻转混合仪上翻转孵育15分钟-1小时。注：也可以直接在步骤2的Protein G Plus磁珠中加入适量抗体或正常IgG进行孵育。c.洗涤：加入500μl的1X TBS，用移液器轻轻吹打重悬Protein G Plus磁珠。置于磁力架上分离10秒，去除上清。重复洗涤三次。按照初始体积的量，用1X TBS重悬Protein G Plus磁珠。注：孵育和洗涤过程中，如果磁珠发生聚团或呈片状属正常现象，不会影响实验结果。4.免疫沉淀(Immunoprecipitation, IP):a.去除非特异性结合(可选做)：步骤3中准备的结合了正常IgG的Protein G Plus磁珠与样品4℃孵育1小时后磁性分离，上清样品用于后续实验。本实验步骤的目的是去除与正常IgG产生非特异性结合的蛋白。b.样品与结合了抗体或正常IgG的Protein G Plus磁珠孵育。按照每500μl蛋白样品加入10μl或20μl磁珠悬浊液的比例加入结合了抗体或正常IgG的Protein G Plus磁珠，置于侧摆摇床或旋转混合仪上，室温孵育2小时或4℃孵育过夜。注1：孵育过程中，如果磁珠发生聚团或呈片状属正常现象，不会影响实验结果。注2：也可先将适量抗体或正常IgG与样品室温孵育1-2小时或4℃孵育过夜后，再加入10-20μl磁珠悬浊液室温孵育1小时。具体见常见问题2。c.磁分离。孵育完毕后，置于磁力架上分离10秒，去除上清。注：可保留部分上清液，用于检测免疫沉淀的效果。d.洗涤。加入500μl的1X TBS，用移液器轻轻吹打重悬磁珠。置于磁力架上分离10秒，去除上清。重复洗涤三次。注：也可以通过检测洗涤得到的洗涤液的OD280来判断是否洗涤完全，若OD280大于0.05，应适当增加洗涤次数。5.洗脱：根据目的蛋白的特点及后续实验要求，可以选择如下方法之一进行洗脱。a.酸性洗脱法：本方法为非变性法，比较快速且高效。洗脱后的蛋白保持原有的生物活性，便于后续分析检测。(a)溶液的配制：酸性洗脱液(0.1M Glycine-HCl, pH3.0)，中和液(0.5M Tris-HCl, pH7.4, 1.5M NaCl)。(b)每10-20μl原始磁珠体积，加入100μl酸性洗脱液，混匀后置于侧摆摇床或旋转混合仪上，室温孵育5分钟。注：孵育时间不宜超过15分钟。注：洗脱液的体积可以酌情适当调整，同时须注意后续的中和液体积也需要作相应调整。(c)孵育完毕后，置于磁力架上分离10秒，将上清转移到新的离心管中，并立刻加入10μl中和液，适当混匀。(d)为了获得最大的洗脱效率，可重复步骤b和c，并将相同样品合并。(e)洗脱并中和的目的蛋白置于4℃待用，或者-20℃或-80℃长期保存。注1：酸性洗脱法虽然高效，但仍可能低于竞争洗脱法或SDS-PAGE上样缓冲液洗脱法。注2：由于目的蛋白的差异可能对酸性洗脱法的洗脱效率有一定的影响，如果对洗脱效率的要求比较高，可对酸性洗脱液的pH在2.5-3.1之间进行一定的调整，相应的中和液的pH值或量也要进行一定的调整，例如100μl酸性洗脱液(0.1M Glycine-HCl, pH2.8)和15μl中和液(1M Tris-HCl, pH8.5)。b.SDS-PAGE上样缓冲液洗脱法：本方法为变性法，得到的蛋白样品适合SDS-PAGE电泳或Western检测。(a)SDS-PAGE上样缓冲液的配制：可以直接使用阿拉丁生产的P0015A SDS-PAGE蛋白上样缓冲液(1X)，或使用阿拉丁生产的P0015 SDS-PAGE蛋白上样缓冲液(5X)或自行参考《分子克隆》等配制5X或2X的SDS-PAGE蛋白上样缓冲液，然后加入水配制成1X的SDS-PAGE蛋白上样缓冲液。通常SDS-PAGE蛋白上样缓冲液含有DTT等还原剂，其洗脱得到的蛋白样品中会含有抗体的轻链和重链。(b)每10-20μl原始磁珠体积的磁珠，加入100μl 1X SDS-PAGE上样缓冲液，95℃加热5分钟。注：洗脱液的体积可以酌情适当调整。(c)置于磁力架上分离10秒，取上清进行SDS-PAGE电泳或Western检测。c.多肽竞争洗脱法：如果目的蛋白是标签蛋白，并使用相应的标签抗体进行免疫沉淀，则可使用相应的多肽进行竞争洗脱。本方法为非变性法，洗脱效率高，且洗脱后的蛋白保持原有的生物活性，便于后续分析检测。以下以Flag标签蛋白为例：(a)3X Flag多肽洗脱液的配制：取适量3X Flag多肽溶解于1X TBS中，使其终浓度为150μg/ml，或稀释5mg/ml的3X Flag多肽溶液至150μg/ml。(b)每10-20μl原始磁珠体积，加入100μl 3X Flag多肽洗脱液(150μg/ml)，混匀后置于侧摆摇床或旋转混合仪上，室温摇晃孵育30-60分钟，或4℃孵育1-2小时。为了提高洗脱效率，可延长孵育时间或重复洗脱。(c)孵育完毕后，置于磁力架上分离10秒，将上清转移到新的离心管中。上清即为洗脱的Flag标签蛋白。(d)洗脱的Flag标签蛋白置于4℃待用，或者-20℃或-80℃长期保存。6.免疫共沉淀(Co-Immunoprecipitation, Co-IP):参考免疫沉淀的方法进行，但免疫共沉淀(Co-IP)通常宜使用未经冻存的新鲜蛋白样品，以确保蛋白复合物不会因为冻融而被破坏。普通的免疫沉淀虽然可以使用冻存的蛋白样品，但通常使用新鲜的蛋白样品更佳。7.抗体的纯化：a.参照步骤3，把Protein G Plus磁珠加入到待纯化的抗体样品中，混匀后室温侧摆摇床或旋转混合仪上孵育1小时。吸去上清，然后用1X TBS洗涤3次。b.参照步骤5a，用适量酸性洗脱液进行洗脱，并用中和液进行中和。常见问题：1.如何提高抗体与磁珠结合效率?磁珠与抗体的结合效率与抗体的种属来源及所属亚型有关，如抗体所属亚型与Protein A、G或A/G的亲和力较低，可以通过增加抗体与磁珠的孵育时间、提高TBS的pH值(8-9)或降低离子强度(25-100mM NaCl)等方法提高亲和力。2.如何提高磁珠在免疫沉淀或免疫共沉淀反应中的特异性?a.参考步骤4b中的备注，可以先将适量抗体与样品进行孵育，形成抗体-抗原复合物，再用Protein A、G或A/G磁珠捕获复合物，这样可以提高抗体与抗原的结合效率，并降低磁珠与样品接触的时间，从而提高沉淀产物的特异性。对于蛋白质/核酸共沉淀或染色质免疫共沉淀也推荐使用此方法。b.参考步骤4a，使用结合了正常IgG的磁珠与蛋白样品预孵育，可以减少抗体的非特异性结合。类似地，也可以在蛋白样品中先加入正常IgG预孵育，然后再加入抗体进行孵育，随后再加入磁珠进行抗体的免疫沉淀。c.设置正常IgG作为抗体的对照，可以确定免疫沉淀或免疫共沉淀产物的特异性。3.如何避免磁珠在储存或使用过程中可能出现的聚集情况？磁珠通常应保存在2-8℃，使用时应避免由于污染而导致的不可逆聚集，或因干燥而导致的聚集。磁珠在低pH的洗脱缓冲液中发生聚集属于正常现象，不影响磁珠的正常使用。在TBS和洗脱缓冲液中添加终浓度为0.1% (v/v)的非离子型去垢剂，如Triton X-100、Tween-20或NP-40，可有效防止磁珠聚集。经过低pH洗脱操作的磁珠可以用TBS洗涤至中性，然后用含有0.1% (v/v) Tween-20的TBS振荡重悬磁珠，并用超声波水浴处理2分钟，即可使磁珠恢复均匀状态，以上处理均不影响磁珠的抗体结合效率。4.如何解决磁珠易粘附在离心管等耗材表面的现象？建议使用低吸附率的耗材进行磁珠操作。另外，在缓冲液中添加0.1% (v/v)的非离子型去垢剂(如Triton X-100、Tween-20或NP-40)可以有效降低磁珠在耗材表面的粘附。5.磁珠在使用过程中出现结块现象？磁珠在使用时如果出现结块现象，容易导致分布不均。出现该问题的原因是磁珠在磁场中放置太久而使磁珠牢固的结合在一起。用超声波水浴处理2分钟即可打散磁珠使其重新分散，但应注意超声处理也会使磁珠在样品溶液中捕获的抗体脱落，所以磁珠在加样后洗脱前不宜使用该方法处理磁珠的结块问题。6.其它常见问题、原因及解决方法： Problem Possible Causes Solution Very few or no target protein exists in the eluate. Protein is not completely eluted. Change elution methods. No target protein expressed. Make sure the protein of interest contains the target protein by Western blot or dot blot analyses. Very low protein expression level. 1.Use larger volume of cell lysate. 2.Optimize expression conditions to raise the protein expression level. Washes are too stringent. Reduce the time and number of washes. Incubation times are inadequate. Increase the incubation time. Interfering substance is present in sample. Lysates containing high concentration of DTT, 2-mercaptoethanol, or other reducing agents may destroy antibody function, and must be avoided. Detection system is inadequate. If Western blot detection is used: 1.Check primary and secondary antibodies using proper controls to confirm binding and reactivity. 2.Verify that the transfer was adequate by usingprestained protein marker or staining the membrane with Ponceau S. 3.Use fresh detection substrate or try a different detection system. Background is too high. Proteins bind nonspecifically to the antibody, insufficient washing on magnetic beads, or the microcentrifuge tubes. 1. Pre-clear lysate with Normal IgG to remove nonspecific binding proteins.2. After suspending beads for the final wash, transfer entire sample to a clean microcentrifuge tube before separation. Washes are insufficient. 1.Increase the number of washes. 2.Prolong duration of the washes, incubating each wash for at least 15 minutes. 3.Increase the salt and/or detergent concentrations in the wash solutions. 4.Centrifuge at lower speed to avoid nonspecific trapping of denatured proteins. Multiple protein bands found in the eluate. The protein is not stable at room temperature. Purify the target protein at lower temperature, such as 4℃. Protein degradation due to proteases activity during purification process. Add protease inhibitors to cell lysate. Non‐specific binding. 1.Prepare cell lysate again. 2.Add additional wash steps. Aladdin's UltraBio™ Protein G Plus Magnetic Beads are based on nano-scale amino magnetic beads covalently coupled with optimized high-quality recombinant Protein G. Compared with UltraBio™ Protein G Magnetic Beads , Protein G Plus Magnetic Beads have stronger ability to specifically bind the corresponding antibodies. With the same amount of magnetic beads, Protein G Plus Magnetic Beads can bind about 30-50% more antibodies. Protein G Plus Magnetic Beads are mainly used for immunoprecipitation (IP), co-immunoprecipitation (Co-IP) or chromatin immunoprecipitation (Ch-IP), and can also be used for antibody purification from serum, cell culture supernatant, or ascites fluid.Protein G is an immunoglobulin binding protein expressed by Streptococcal bacteria type C or G. Protein A is a cell wall surface protein found in Staphylococcus aureus with a molecular weight of 42kDa. Protein A and Protein G are functionally similar and can bind specifically to mammalian immunoglobulin (Ig), usually to the Fc region of the immunoglobulin, but it has been reported that Protein A also binds to the Fab region of the human VH3 family, and Protein G sometimes binds to the Fab region as well. At the same time, Protein A and Protein G differ in their ability to bind to different immunoglobulin subclasses. Recombinant Protein A and G with appropriate modifications bound in a certain way to magnetic beads can be used for immunoprecipitation or antibody purification. The Protein G Plus used in this magnetic bead optimizes the steric hindrance effect of Protein G to bind 3 IgG molecules at the same time without changing the basic performance of Protein G, and has a stronger ability to specifically bind the corresponding antibody. With the same amount of magnetic beads in some cases, Protein G Plus magnetic beads can bind approximately 30-50% more antibodies.Like Protein G Magnetic Beads, Protein G Plus Magnetic Beads are suitable for immunoprecipitation of human IgG1,IgG2,IgG3,IgG4,mouse IgG1,IgG2a,IgG2b,IgG3,rat IgG1,IgG2a,IgG2b, IgG2c,and polyclonal antibodies from rabbit and goat. Protein A magnetic beads are suitable for immunoprecipitation of human IgG1,IgG2,IgG4,mouse IgG2a,IgG2band rabbitrabbit IgG. The following table shows the binding capability of Aladdin's Protein A, Protein G and Protein A/G magnetic beads to common immunoglobulin subclasses of human, mouse and rat, and the total binding capacity of different species.SpeciesIgProtein AProtein GA+GHumanIgG1++++++++++++IgG2++++++++++++IgG3-++++++++IgG4++++++++++++IgA++-++IgD++-++IgE++-++IgM++-++MouseIgG1+++++++++IgG2a++++++++++++IgG2b+++++++++IgG3++++++++IgM+/--+/-RatIgG1-++IgG2a-++++++++IgG2b-++++IgG2c+++++IgM+/--+/-Total IgProtein AProtein GA+GHuman++++++++++++Mouse+++++++++Rat+/-++++Rabbit+++++++++++Goat-++++Chicken-++Cow++++++++++Guinea Pig++++++++++Hamster+++++Horse++++++++++Pig+++++++++Sheep+/-++++ ++++, Strong Binding ++~+++, Medium Binding +, Weak Binding +/-, Weak or No Binding -, No BindingThe recombinant Protein G Plus in this product binds specifically to the Fc region of most mammalian IgGs and has a molecular weight of approximately 25kDa. The recombinant Protein G Plus has been modified to reduce non-specific binding by retaining only the amino acid sequences that bind with the Fc region of IgG. Each Protein G Plus molecule can bind up to 3 IgG molecules.UltraBio™ Protein G Plus Magnetic Beads can specifically bind to the relevant antibodies and can be applied to experiments such as immunoprecipitation or purification of target proteins or their protein complexes with the aid of a magnetic stand. Please refer to Figure 1 for the flow chart of this product for immunoprecipitation.Figure 1. The flow chart for immunoprecipitation with Aladdin's UltraBio™ Protein G Plus magnetic beads .High specificity and high binding capacity Precautions ： It has been tested that repeated freeze-thaws for more than 3 times will not affect the performance of this product.This product should be maintained at a pH of 6-8. Do not centrifuge, dry or freeze the magnetic beads. Long time exposure of the beads to magnetic field will cause beads to agglomerate.This product should be properly resuspended in solution by gentle pipetting prior to use. Do not vortex to avoid the denaturation of the antibody.When performing immunoprecipitation, it is recommended to set up both positive and negative controls appropriately.Protein samples should be purified as soon as possible after collection and should always be placed at 4℃ or on ice to minimize protein degradation or denaturation. Protein degradation can also be inhibited by adding appropriate protease inhibitors, such as Protease Inhibitor Cocktail for General Use ,Protease and Phosphatase Inhibitor Cocktail for General Use (MS-safe, 50X) , Protease Inhibitor Cocktail for Mammalian Cell and Tissue Extracts , Protease and Phosphatase Inhibitor Cocktail for Mammalian Cell and Tissue Extracts , etc.If using a vacuum pump to aspirate the supernatant, the strength of the vacuum pump should be controlled properly to avoid the aspiration of magnetic beads.The beads may agglomerate when eluted with acidic solutions, which is normal and does not affect the normal use of the beads. 0.1% non-ionic detergent (e.g., Triton X-100, Tween-20 or NP-40) is effective in preventing agglomeration and does not affect the antibody binding efficiency of the beads.High concentrations of DTT, mercaptoethanol, guanidine hydrochloride, etc. may have a certain effect on the binding of this product to tagged proteins, but Cell lysis buffer forWestern and IP RIPA Lysis Buffer orNP-40 Lysis Buffer etc. are fully applicable. For selection guide of different lysis buffers produced by , please refer to our website at: http://www.aladdin-e.com/support/lysis-buffer.htm。This product is for R&D only. Not for drug, household, or other uses.For your safety and health, please wear a lab coat and disposable gloves during the operation. Instructions for Use ： 1.Preparation of protein samples.a.Choose an appropriate lysis buffer for preparing cell or tissue lysates, such as Protein A Magnetic Beads 1ml P2102-5ml Protein A Magnetic Beads 5ml P2105-1ml Protein G Magnetic Beads 1ml P2105-5ml Protein G Magnetic Beads 5ml P2106-1ml Protein G Plus Magnetic Beads 1ml P2106-5ml Protein G Plus Magnetic Beads 5ml P2108-1ml Protein A+G Magnetic Beads 1ml P2108-5ml Protein A+G Magnetic Beads 5ml