链霉亲和素磁珠与生物素化配体如蛋白、抗体、核酸等具有高度的特异反应，免去了活化、偶联、封闭等步骤，使用方便。链霉亲和素修饰磁珠粒径为5 μm，具有较高的链霉亲和素载量及极高的亲水性；超顺磁性，磁响应性好；具有优良的再分散稳定性和磁稳定性。5 μm磁珠均一性好，适用于单细胞测序、液相探针捕获、核酸Pull-down、细菌检测等应用场景。
产品信息
浓度
| 10 mg/mL
|
粒径
| 约 5 μm
|
表面电位
| 约-20 mV
|
亲和素载量
| 70-80 μg/mg beads
|
生物素化BSA偶联量
| 10-15 μg/mg beads |
保存条件
| 密封，4℃，禁止冷冻，使用前请充分混匀 |
扫描电镜
图1. 链霉亲和素磁珠 (5μm) SEM照片
使用说明
以偶联生物素化抗体为例，可根据不同的实验需求进行调整。
链霉亲和素磁珠 (5μm) 具有良好的亲水性和单分散性，使用前振荡混匀后即可使用。
使用溶剂和材料
- CB：0.02 M 碳酸盐缓冲液，pH=9.0
- PBS：0.02 M 磷酸盐缓冲液，含 0.9% NaCl，pH=7.4
- 清洗液：15 mM PBS pH 7.4，0.1% Tween 20
- 保存液：15 mM PBS pH 7.4，0.1% Tween 20（含一定量甘氨酸、酪蛋白及防腐剂）
实验步骤
1. 抗体生物素化
- 取100 μg抗体，用CB稀释至100 μL；
- 边涡旋边迅速加入1 mg/mL PEG化生物素2 μL（需自备）；
- 37℃，孵育45 min；
- 采用4000 g、10 min超滤离心四次，PBS重悬至1 mg/mL。
2. 偶联生物素化抗体
取1 mL链霉亲和素修饰磁珠（10 mg/mL），涡旋加入20 μL生物素化抗体（参考用量20 μg），37℃摇床孵育1 h。注意：在摇床孵育过程中，试管横放避免磁珠沉降导致偶联效率受影响。
磁分离并用清洗液洗涤4次，用保存液重悬至需要浓度。
注意事项
1. 磁珠取用前应充分混匀，防止取用改变磁珠浓度，避免长时间超声对磁珠表面破坏；
2. 磁珠取出后，使用前请进行磁分离并用纯水或所用缓冲溶液清洗2-3遍；
3. 磁珠使用和保存过程中应避免冻融。
Streptavidin magnetic beads exhibit highly specific reactions with biotinylated ligands such as proteins, antibodies, and nucleic acids, eliminating the need for activation, coupling, and blocking steps, and are easy to use. The streptavidin-modified magnetic beads have a particle size of 5 μm, high streptavidin loading capacity, and excellent hydrophilicity. They are superparamagnetic with good magnetic responsiveness and possess outstanding redispersibility and magnetic stability. The 5 μm beads have good uniformity and are suitable for applications such as single‑cell sequencing, liquid‑phase probe capture, nucleic acid pull‑down, and bacterial detection.
Product Information
| Parameter | Value |
|---|
| Concentration | 10 mg/mL | | Particle size | approx. 5 μm | | Surface potential | approx. –20 mV | | Streptavidin loading | 70–80 μg/mg beads | | Biotinylated BSA coupling capacity | 10–15 μg/mg beads | | Storage conditions | Sealed, 4°C, do not freeze. Shake well before use. |
|
Scanning Electron Micrograph
Figure 1. SEM image of streptavidin magnetic beads (5 μm)
Instructions for Use
The following protocol uses biotinylated antibody as an example; it can be adjusted according to different experimental requirements.
The streptavidin magnetic beads (5 μm) have good hydrophilicity and monodispersity. They can be used directly after vortexing to mix.
Solvents and Materials Used
CB: 0.02 M carbonate buffer, pH 9.0
PBS: 0.02 M phosphate buffer containing 0.9% NaCl, pH 7.4
Washing buffer: 15 mM PBS pH 7.4, 0.1% Tween 20
Storage buffer: 15 mM PBS pH 7.4, 0.1% Tween 20 (containing a certain amount of glycine, casein, and preservative)
Procedure
1. Biotinylation of antibody
Dilute 100 μg of antibody with CB to 100 μL.
Quickly add 2 μL of 1 mg/mL PEGylated biotin (To be prepared by the customer) while vortexing.
Incubate at 37°C for 45 min.
Perform ultrafiltration centrifugation four times at 4000 × g for 10 min, then resuspend in PBS to 1 mg/mL.
2. Coupling of biotinylated antibody
Take 1 mL of streptavidin‑modified magnetic beads (10 mg/mL).
Add 20 μL of biotinylated antibody (recommended amount 20 μg) while vortexing.
Incubate at 37°C on a shaker for 1 h. Note: During shaking incubation, lay the tube horizontally to prevent bead sedimentation, which could affect coupling efficiency.
Perform magnetic separation and wash four times with washing buffer. Resuspend in storage buffer to the desired concentration.
Precautions
Before use, thoroughly mix the magnetic beads to avoid changes in bead concentration during aliquoting. Avoid prolonged sonication, which may damage the bead surface.
After taking the required amount of beads, perform magnetic separation and wash 2–3 times with pure water or the buffer solution to be used before proceeding with the experiment.
Avoid freeze‑thaw cycles during the use and storage of the magnetic beads.
ZJ26F0737820
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