Description

SA200 Streptavidin Magnetic Beads are 200 nm streptavidin-coated magnetic beads designed for rapid and efficient capture of biotinylated molecules. The bead surface is functionalized with covalently coupled recombinant streptavidin and further blocked with BSA, helping reduce non-specific adsorption while maintaining strong biotin-binding performance.

SA200 beads are coated with polystyrene and supplied as a 10 mg/mL suspension. As a solid-phase matrix, streptavidin magnetic beads can bind a wide range of biotinylated complexes, including small molecules, peptides, proteins, antibodies, carbohydrates, lectins, oligonucleotides, DNA, and RNA. They are suitable for nucleic acid purification, protein or peptide purification, immunodetection, cell separation, pathogen detection, and NGS-related capture workflows.

With 1,200 pmoles of free biotin binding capacity per mg, 500 pmoles of biotinylated oligonucleotide capacity, and 20 μg of biotinylated antibody capacity, SA200 provides high binding capacity, efficient liquid-phase reaction kinetics, good suspension performance, and rapid magnetic separation that is typically completed within approximately 1 minute.

Specifications

Bead Size	200 nm
Bead Type	Streptavidin magnetic beads
Coating Material	Polystyrene
Surface Functionalization	Covalently coupled monolayer recombinant streptavidin with BSA blocking
Solid Content	10 mg/mL
Biotin Binding Capacity	1,200 pmoles / mg
Biotinylated Oligonucleotide Capacity	500 pmoles / mg
Biotinylated Antibody Capacity	20 μg / mg
Product Packaging	Available in various specifications: 1 mL, 5 mL, 20 mL
Storage Buffer	10 mM PBS, pH 7.4, containing 0.02% ProClin 300 and 0.02% Tween 20
Storage Condition	2–10 °C, store upright, do not freeze
Shelf Life	24 months

Applications

Next-generation sequencing (NGS) — capture and enrichment of biotinylated DNA/RNA fragments
Specific sequence capture — isolation of target biotinylated nucleic acid sequences
Protein and peptide purification — purification of biotinylated proteins or peptides
Immunodetection — ELISA, Western blot, immunochemiluminescence, and related assay workflows
Cell separation — magnetic isolation of biotin-labeled or antibody-labeled cells
Pathogen detection — biotin-based molecular and immunological detection workflows
Antibody purification — affinity capture of biotinylated antibody complexes
Mass spectrometry sample preparation — enrichment of biotinylated proteins or peptides for downstream analysis

Compatible Molecules and Experimental Workflows

Compatible Molecules	Small molecules, peptides, proteins, antibodies, carbohydrates, lectins, oligonucleotides, DNA/RNA
Supported Experiments	Western blot, ELISA, Northern blot, qPCR, mass spectrometry analysis, antibody purification, cell sorting, immunochemiluminescence

Binding Capacity

1 mg of SA200 streptavidin magnetic beads can bind to:

1,200 pmoles of free biotin
500 pmoles of biotinylated oligonucleotides
20 μg of biotinylated antibodies

The binding capacity for double-stranded DNA depends on the length of the DNA fragments.

Advantages

Rapid: High magnetic content enables magnetic separation to be completed generally within approximately 1 minute.
Specific: Strong specificity, good monodispersity, good suspension performance, and reduced physical and non-specific adsorption.
Efficient: High binding capacity, large specific surface area, and high surface biological ligand activity.
Safe: Low-charge and neutral magnetic beads made with stable polymer materials, with extremely low iron leakage.

Principle

As a solid-phase matrix, streptavidin-conjugated magnetic beads can bind to various biotinylated complexes in a simple, rapid, and efficient manner, including small-molecule peptides, proteins, antibodies, carbohydrates, lectins, and oligonucleotide DNA/RNA. Therefore, they are applicable in molecular and immunodetection, cell sorting, cDNA expression library construction, drug screening, nucleic acid purification, protein purification, and related downstream applications.

Storage

Store at 2–10 °C.
Store the magnetic bead container upright to ensure that settled beads remain protected by storage buffer.
Avoid freezing. Freezing may reduce magnetic bead activity.
Prevent beads attached to the tube wall from drying, as dehydration may reduce biological activity.

Precautions

The binding capacity of streptavidin magnetic beads is related to the size of the specific target molecule.
Ensure there is no excessive free biotin in the sample, as free biotin binds to streptavidin more easily than large-molecular-weight target molecules.
For PCR product solutions amplified with biotinylated primers, try to remove free biotinylated primers before binding to the magnetic beads, because biotin-labeled primers bind more readily than biotinylated DNA fragments.
Free biotinylated primers can be removed by ultrafiltration, microdialysis, or general DNA purification and recovery methods.
It is recommended to optimize the dosage of magnetic beads through titration in each application. The size of the ligand molecule and the degree of biotinylation may affect binding capacity.
The ratio of magnetic beads to biotinylated ligands directly affects experimental results. Once saturation adsorption is reached, increasing the concentration of biotinylated ligands will not further improve target-binding capacity.
For preparation of biotinylated ligands, biotinylation reagents from manufacturers such as Pierce or Sigma are recommended.
Biotin labeling can be applied to amines, thiols, carboxyl groups, carbohydrates, tyrosine and histidine side chains, guanidines, and cytosine bases.
Biotinylation may cause loss of target molecule activity, so precautions should be taken according to the specific application.
In DNA synthesis, biotin is generally labeled at the 5’-end of oligonucleotide primers. For protein biotinylation, biotin-X-NHS Ester from Pierce or Sigma can be used.
After magnetic beads bind to the ligand, ensure that the target substance is free in solution and that its ligand-binding sites are exposed.

Operational Procedures (For Reference)

A. Magnetic Bead Preparation

1. Before use, vortex the magnetic bead suspension thoroughly. Ultrasonic dispersion can also be used by carefully placing the tube in a standard ultrasonic cleaner and sonicating for approximately 3 minutes. Use a pipette to transfer the required volume of magnetic beads into a centrifuge tube.

2. Place the centrifuge tube on a magnetic rack. Separation is typically complete within approximately 1 minute. Use a pipette to remove the liquid.

3. Add the washing solution specified for the experiment, cap the tube, and mix thoroughly by vortexing. Then perform magnetic separation and remove the liquid.

4. Repeat the washing step 1–2 times, and resuspend the magnetic beads in an appropriate volume of solution.

For antibody- or protein-related experiments: Wash the SA magnetic beads 2–3 times with PBS or physiological saline buffer before use.
For nucleic acid-related experiments: Wash the SA magnetic beads with 1× B&W Buffer at least 3 times before use.

Formulation of 2× B&W Buffer: 10 mM Tris-HCl, pH 7.5, 1 mM EDTA, 2 M NaCl.

This product does not contain ribonuclease (RNase). For RNA-related experiments, pre-treat the SA magnetic beads to remove RNase:

Wash the SA magnetic beads twice with Wash Buffer I: DEPC-treated 0.1 M NaOH and DEPC-treated 0.05 M NaCl, 2 minutes per wash.
Then wash once with Wash Buffer II: DEPC-treated 0.1 M NaCl, and finally resuspend the SA magnetic beads in Wash Buffer II.

B. Binding to Biotinylated Ligands

1. Binding of Streptavidin Magnetic Beads to Biotin-Antibody or Biotin-Peptides

Calculate the required amounts of magnetic beads and biotinylated antibody. Each mg of streptavidin magnetic beads can bind up to 20 μg of antibody or 300 pmol of biotinylated peptide. Saturation levels of antibody or peptide are generally not required.
After resuspending the magnetic beads, incubate them with the biotinylated antibody at room temperature for 30 minutes, mixing by rotation.
After incubation, place the centrifuge tube on a magnetic rack for 2 minutes and remove the supernatant.
Wash the magnetic beads 4–5 times with PBS/BSA.
Resuspend and dilute the magnetic beads to the desired concentration for downstream experiments.

2. Binding of Streptavidin Magnetic Beads to Nucleic Acids

Take an appropriate amount of pre-washed magnetic beads.
Resuspend the magnetic beads in 2× B&W Buffer to a final concentration of 1 μg/μL or a concentration suitable for the experiment.
Add an equal volume of biotinylated DNA/RNA solution.
At room temperature, mix by rotating or gently tapping the centrifuge tube. Incubate for approximately 10 minutes for ~30 bp fragments, and approximately 15 minutes for ~1 kb fragments.
After incubation, place the centrifuge tube on a magnetic rack for 1–2 minutes and remove the liquid.
Wash the magnetic beads 2–3 times with 1× B&W Buffer.
Finally, resuspend the magnetic beads in a solution suitable for downstream experiments.

C. Dissociation of Streptavidin Magnetic Beads from Antibodies/Proteins and Nucleic Acids

1. Antibody / Protein Elution

Resuspend the bound magnetic beads in 0.1% SDS and heat at approximately 95 °C for 5 minutes. Note: This may reduce protein activity.

2. Nucleic Acid Elution

Use TE buffer at pH 8.0 and heat at 95 °C for 5 minutes. This can dissociate approximately 98% of nucleic acids.

FAQ

Q: What is the biotin binding capacity of SA200 streptavidin magnetic beads?
A: 1 mg of SA200 binds approximately 1,200 pmoles of free biotin, 500 pmoles of biotinylated oligonucleotides, and 20 μg of biotinylated antibodies.

Q: What is the particle size of SA200?
A: SA200 streptavidin magnetic beads have a bead size of 200 nm.

Q: Can SA200 beads be used for NGS workflows?
A: Yes. SA200 beads can be used for NGS-related biotinylated DNA/RNA capture and specific sequence capture workflows.

Q: What types of molecules can SA200 bind?
A: SA200 can bind biotinylated small molecules, peptides, proteins, antibodies, carbohydrates, lectins, oligonucleotides, DNA, and RNA.

Q: How fast is magnetic separation?
A: Magnetic separation is typically completed within approximately 1 minute under standard magnetic rack conditions.

Q: Can SA200 magnetic beads be frozen?
A: No. Freezing should be avoided because it may reduce magnetic bead activity.

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Documents

User Manual

Application Performance Data

Streptavidin Beads (200 nm) Leadonano™