Strep-Tactin Magnetic Beads
The Strep-Tag II is a small 8‑amino acid tag (WSHPQFEK) with a molecular weight of about 1 kDa, which does not affect the structure of the fusion protein and is widely used for detection and purification. Strep‑Tactin Magnetic Beads contain a mutant streptavidin ligand with an affinity for Strep‑Tag II that is at least 10‑fold higher than the wild‑type protein. Its binding to the tag is weaker than that to biotin, allowing mild elution conditions (e.g., with desthiobiotin). While the beads can also bind biotin, elution of biotinylated molecules requires harsher conditions.
Strep‑Tactin Magnetic Beads are a next‑generation affinity magnetic bead tool designed for life science research. They consist of mutant streptavidin covalently coupled to superparamagnetic beads, enabling specific binding to Strep‑Tag II‑tagged or (desthio)biotin‑labeled proteins. Combined with magnetic separation, the beads allow rapid purification and detection of target proteins. The purification is gentle and efficient, typically yielding >99% pure protein in a single step while preserving biological activity-achieving an optimal balance of speed, yield, and purity.
The product is suitable for tagged‑protein purification (Strep‑Tag II), pull‑down assays, and other applications. It is available in multiple formats including 1.5 mL, 5 mL, 10 mL, and 50 mL sizes.
Product parameters:
|
Product name |
Strep-Tactin Magnetic Beads |
|
Product Size |
1.5 mL/5 mL/10 mL/50 mL |
|
Matrix spherical |
Superparamagnetic magnetic beads |
|
Ligand |
Mutant of streptavidin (~6 mg/mL). |
|
Particle size |
30-150 μm |
|
Binding Capacity |
≥ 7 mg Strep-tag II protein /mL of beads |
|
Concentration |
10% (v/v) |
|
Storage Buffer |
1X PBS (0.I%Tween-20, 0.05%NaN3) |
|
Application |
Strep-Tag II-tagged Protein Purification, Pull-down Assay |
|
Storage |
Store at 4°C for 12 months, avoid lower temperature storage |
1. Can magnetic beads be stored to -20°C and below?
A: No, you cannot. Magnetic bead series products cannot be stored and transported at low temperature, and must be stored in accordance with the instructions in the manual, and stored in an environment of 2-8°C.
2. Is there a specific species range for the purification of fusion proteins (Strep-Tag II tags) using these beads?
A: There is no defined species range. Can be used for isolation and purification of Strep-Tag II-tagged proteins from any expression system, including baculovirus, mammalian cells, yeast, and bacteria.
3. How to improve target protein recovery?
Answer: 1prolonged the incubation time of protein solution and magnetic beads; 2. Add appropriate protease inhibitors to prevent the degradation of the target protein; 3. Increase the amount of magnetic beads; 4. Extend the elution time or increase the number of elutions.
4. How to improve the purity of the target protein?
Answer: 1. Appropriate protease inhibitors are added during purification to prevent degradation of the target protein. 2. Extend the washing time and increase the number of washes.
5. Are magnetic beads reusable?
A: It can be reused. When reusing, it is recommended to use different or new magnetic beads when purifying different types of proteins to prevent cross-contamination.
