琼脂糖基质磁性微球（Magnetic Agarose Beads）系列产品具有超顺磁性、快速磁响应性、丰富羟基官能团和相对集中的粒径等特点，能够在特殊化学试剂的作用下，将多肽、蛋白、抗体、寡聚核苷酸等生物配体共价偶联到微球表面，是医学与分子生物学研究中重要的载体工具。本产品采用独特生产工艺制备的磁性琼脂糖微球，粒径分布在30-100 μm，粒径适中，更适合生物检测和纯化实验的需求。
糊精琼脂糖磁珠（MBP标签）可实现MBP融合蛋白的一步纯化，结合的融合蛋白可采用10 mM麦芽糖进行温和洗脱，能有效保护标签蛋白的活性；若需去除MBP融合部分，可通过位点特异性蛋白酶切除。当MBP融合蛋白与糊精琼脂糖磁珠混合时会被特异性吸附，在磁力作用下，融合蛋白可从表达体系中快速分离。
| 项目 | 性能 |
|---|
| 基质 | 磁性琼脂糖微球 | | 配体 | 糊精 | | 载量 | 40-50 mg MBP蛋白/ml 磁珠 | | 平均粒径 | 50-70 μm | | 储存缓冲液 | 含20%乙醇的1×PBS | | 磁珠体积 | 磁珠体积占悬浮液体积的20% | | 储存温度 | 2-8℃ |
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使用方法
1. 缓冲液准备
实验所用水和各类缓冲液，使用前建议用0.22 μm或0.45 μm滤膜过滤，去除杂质，避免影响实验效果。
平衡/洗杂液：20 mM Tris-HCl，200 mM NaCl，1 mM EDTA，pH 7.4
洗脱液：20 mM Tris-HCl，1 mM EDTA，10 mM 麦芽糖，pH 7.4
注意：平衡液和洗脱液中可加入1 mM DTT或10 mM β–巯基乙醇。
2. 样品准备
上柱前需确保样品溶液具有合适的离子强度和pH值，可采用以下两种方式调节：用平衡液稀释样品或细胞培养液；或用平衡液对样品进行透析。样品上样前，建议离心处理或用0.22 μm或0.45 μm滤膜过滤，以减少杂质、提高蛋白纯化效率，并防止堵塞柱子。
3. 磁珠准备
(1) 根据产品性能指标准备适量的糊精琼脂糖磁珠（MBP标签），磁珠体积占悬浮液总体积的20%。将磁珠悬浮液反复颠倒，充分混匀；以500 µL磁珠悬浮液（含磁珠100 µL）为例，将其置于离心管中，再将离心管放入磁分离器，静置约1 min，待溶液澄清后，用移液器吸弃上清液。
(2) 磁珠平衡：将离心管从磁分离器上取下，加入500 µL平衡液，用枪头反复吹打5次，充分混匀；将离心管再次置于磁分离器，静置约1 min，待溶液澄清后吸弃上清液；重复此平衡步骤2次。
4. MBP标签蛋白纯化
(1) 将含有MBP标签融合蛋白的样品加入到处理好的磁珠中，反复颠倒离心管充分混匀；将离心管置于混合仪上，室温孵育30 min以上（具体孵育时间可根据实际结合效果调整）。
(2) 磁珠洗杂：将离心管置于磁分离器，静置约1 min，待溶液澄清后，用移液器移出上清液并保留，以备后续取样检测；向离心管中加入1 mL洗杂液，用枪头反复吹打5次，充分混匀；将离心管放回磁分离器，静置约1 min，待溶液澄清后吸弃上清液；至少重复此洗杂步骤2次。
(3) 洗脱：向上述离心管中加入300 µL洗脱液，用移液器吹打5次混匀；室温下将离心管置于翻转混合仪，或手工轻轻翻转离心管，孵育5-10 min后，将离心管置于磁分离器，静置约1 min，待溶液澄清后，吸取上清液，收集洗脱组分（即为目标蛋白）；重复此洗脱操作2-3次，分别收集各洗脱组分，留待后续检测。
注意事项
1. 磁珠操作全程需轻柔，避免剧烈震荡和反复吹打，防止磁珠破损，影响MBP融合蛋白的结合效率。
2. 孵育、磁分离时间可根据实验实际情况适当调整，确保磁珠充分吸附目标蛋白，提高纯化效率。
3. 缓冲液需现配现用，或按要求密封储存，避免变质；加入DTT或β–巯基乙醇后，需尽快使用，防止其失效。
4. 磁珠储存需严格控制在2-8℃，避免冷冻或高温，防止磁珠失活；储存期间需定期轻轻颠倒混匀，防止磁珠团聚。
5. 洗脱后的目标蛋白需及时处理或低温保存，避免蛋白变性，影响后续实验使用。
Agarose Matrix Magnetic Microspheres (Magnetic Agarose Beads) series products feature superparamagnetism, fast magnetic response, abundant hydroxyl functional groups, and a relatively narrow particle size distribution. They can covalently couple biological ligands such as peptides, proteins, antibodies, and oligonucleotides to the microsphere surface under the action of specific chemical reagents, making them important carrier tools in medical and molecular biology research. This product is manufactured using a unique production process to produce magnetic agarose microspheres with a particle size distribution of 30–100 μm. The moderate particle size makes them more suitable for the needs of bioassays and purification experiments.
Dextran Agarose Magnetic Beads (MBP tag) enable one‑step purification of MBP fusion proteins. The bound fusion proteins can be gently eluted with 10 mM maltose, effectively preserving the activity of the tagged protein. If removal of the MBP fusion partner is desired, it can be achieved by site‑specific protease cleavage. When MBP fusion proteins are mixed with Dextran Agarose Magnetic Beads, they are specifically adsorbed, and under magnetic force, the fusion proteins can be rapidly separated from the expression system.
| Property | Description |
|---|
| Matrix | Magnetic agarose microspheres | | Ligand | Dextran | | Binding capacity | 40–50 mg MBP protein/mL beads | | Average particle size | 50–70 μm | | Storage buffer | 1× PBS containing 20% ethanol | | Bead volume | 20% of suspension volume | | Storage temperature | 2–8°C |
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Instructions for Use
1. Buffer preparation
All water and buffers used in the experiment should be filtered through a 0.22 μm or 0.45 μm filter before use to remove impurities that might affect the results.
Equilibration/wash buffer: 20 mM Tris‑HCl, 200 mM NaCl, 1 mM EDTA, pH 7.4
Elution buffer: 20 mM Tris‑HCl, 1 mM EDTA, 10 mM maltose, pH 7.4
Note: 1 mM DTT or 10 mM β‑mercaptoethanol can be added to both the equilibration and elution buffers.
2. Sample preparation
Before loading, ensure the sample solution has appropriate ionic strength and pH. Adjust using one of the following methods: dilute the sample or cell culture medium with equilibration buffer; or dialyze the sample against equilibration buffer. It is recommended to centrifuge the sample or filter it through a 0.22 μm or 0.45 μm filter before loading to reduce impurities, improve protein purification efficiency, and prevent column clogging.
3. Bead preparation
(1) Prepare an appropriate amount of Dextran Agarose Magnetic Beads (MBP tag) according to the product specifications. The bead volume constitutes 20% of the total suspension volume. For example, take 500 μL of bead suspension (containing 100 μL of beads) and place in a centrifuge tube. Place the tube in a magnetic separator and let stand for about 1 min until the solution becomes clear. Aspirate and discard the supernatant.
(2) Bead equilibration: Remove the tube from the magnetic separator. Add 500 μL of equilibration buffer and pipette up and down 5 times to mix thoroughly. Place the tube back on the magnetic separator, let stand for about 1 min until the solution clears, then aspirate and discard the supernatant. Repeat this equilibration step twice.
4. Purification of MBP‑tagged protein
(1) Add the sample containing the MBP‑tagged fusion protein to the prepared beads. Invert the tube repeatedly to mix thoroughly. Place the tube on a mixer and incubate at room temperature for at least 30 min (incubation time can be adjusted according to actual binding efficiency).
(2) Bead washing: Place the tube on the magnetic separator, let stand for about 1 min until the solution clears, then transfer the supernatant to a new tube (keep for subsequent analysis if needed). Add 1 mL of wash buffer to the tube and pipette up and down 5 times to mix thoroughly. Place the tube back on the magnetic separator, let stand for about 1 min until the solution clears, then aspirate and discard the supernatant. Repeat this washing step at least twice.
(3) Elution: Add 300 μL of elution buffer to the tube and pipette up and down 5 times to mix. Incubate at room temperature on a rotator mixer or by gently inverting the tube manually for 5–10 min. Place the tube on the magnetic separator, let stand for about 1 min until the solution clears, then aspirate the supernatant (this is the eluted fraction containing the target protein). Repeat the elution 2–3 times, collecting each eluted fraction for subsequent analysis.
Precautions
Always handle the beads gently throughout the procedure; avoid vigorous shaking and excessive pipetting to prevent bead damage that could affect the binding efficiency of the MBP fusion protein.
Incubation and magnetic separation times may be adjusted according to the actual experimental conditions to ensure sufficient capture of the target protein and improve purification efficiency.
Buffers should be freshly prepared or stored sealed as required to avoid degradation. After adding DTT or β‑mercaptoethanol, use them as soon as possible to prevent loss of activity.
Beads must be stored strictly at 2–8°C, avoiding freezing or high temperatures to prevent inactivation. During storage, gently invert the container periodically to prevent bead aggregation.
The eluted target protein should be processed promptly or stored at low temperature to avoid denaturation that could affect subsequent experiments.
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