SiDirect Beads

What it means: Magnetic Beads are polymer- or silica-matrix particles with embedded iron oxide cores that respond to an external magnetic field. They can be pulled out of solution rapidly using a permanent magnet or magnetic separation rack.

Why it matters:

• Enables hands-free wash and separation steps — no centrifuge or filter column needed.
• Particle size (50 nm–4.5 µm range) determines separation speed, surface area per mg, and suspension stability.
• Iron oxide content (18–80%) governs how fast beads respond to a magnet — higher content = faster separation.
• Surface functional groups determine which coupling chemistry and biomolecule classes can be immobilized.

How to interpret here: This product is a Magnetic Bead format. Select the size and surface chemistry variant that matches your conjugation strategy and magnetic separation setup. Check the specification sheet for magnetic content and recommended separator.

Tip: Always resuspend by bath sonication before use — magnetic beads settle during storage and may not be fully redispersed by vortexing alone.

What it means: Unmodified surface indicates these particles have a polymer or silica coating that provides aqueous stability without a defined reactive functional group for direct bioconjugation. The surface is intentionally designed for low non-specific binding.

Why it matters:

• Suitable for applications where no covalent conjugation is needed — e.g., nucleic acid isolation via salt/pH-mediated binding to the bead surface.
• Can be used as a starting material for custom ligand exchange or surface modification protocols.
• Low non-specific protein binding reduces background in nucleic acid extraction workflows.
• No activation or coupling reagents needed for intended nucleic acid capture applications.

How to interpret here: This product has an Unmodified surface — it captures nucleic acids through silica or polymer–DNA interactions under chaotropic or binding buffer conditions, not through covalent chemistry. Follow the kit protocol for buffer conditions that optimize nucleic acid binding and release.

Tip: Do not use this product for direct covalent protein or antibody conjugation without first introducing functional groups via ligand exchange or surface modification.

What it means: Particle Size refers to the mean hydrodynamic diameter of the particle in suspension. Available sizes: 1 um.

Why it matters:

• Bead size affects surface area, suspension stability, and magnetic separation speed.
• Smaller particles have higher surface area per mg — more binding sites per weight of material.
• Larger particles settle faster under gravity and separate faster with a magnet.
• Select size based on your magnetic separation speed requirements, surface area needs, and assay geometry.

How to interpret here: This product is available in 1 um. Smaller sizes have more surface area per mg; larger sizes separate faster with a magnet.

Tip: Particle size is measured by DLS (dynamic light scattering) and represents the hydrodynamic diameter, which includes surface coating — actual iron core size is smaller as shown in TEM measurements in the specification sheet.

What it means: Unmodified indicates the particle has no specific reactive surface group designed for covalent bioconjugation. These particles interact with nucleic acids through non-covalent mechanism (e.g., silica–DNA binding under chaotropic conditions, or size-selective PEG precipitation in the case of purification beads).

Why it matters:

• No activation or coupling reagents needed for intended nucleic acid capture applications.
• Nucleic acid binding and release controlled by buffer composition (binding buffer, wash buffers, elution buffer) rather than surface chemistry.
• Well suited for automated, high-throughput DNA/RNA extraction workflows.
• Predictable lot-to-lot performance because nucleic acid capture depends on buffer conditions rather than variable covalent coupling efficiency.

How to interpret here: This product is Unmodified. It is optimized for nucleic acid isolation, not covalent protein conjugation. Use it with the recommended buffer system (kit buffers or the protocol in Documents) for optimal nucleic acid recovery. Do not attempt EDC or NHS-based coupling reactions.

Tip: Check the protocol for optimal bead:sample volume ratios, lysis buffer composition, and elution temperature to maximize nucleic acid yield and purity.

What it means: Aqueous dispersion means this product is supplied as a colloidal suspension in an aqueous buffer (typically PBS, DI water, or a proprietary storage buffer). The particles are dispersed and ready for use in water-based biological applications without any solvent exchange step.

Why it matters:

• Compatible directly with cell culture media, PBS, HEPES, and other standard biological buffers.
• No solvent exchange or phase transfer required before use in aqueous assay protocols.
• Aqueous colloidal stability maintained by surface coating (polymer, PEG, or functional group layer).
• Bath sonication before use ensures complete resuspension after storage sedimentation.

How to interpret here: This product is in Aqueous dispersion. It can be used directly in your assay buffer after resuspension. Confirm compatibility with your specific buffer conditions (ionic strength, pH, protein concentration) by checking the product specification sheet or running a small-scale stability test.

Tip: High ionic strength buffers (>500 mM) or pH extremes outside the specification range may compromise colloidal stability. Always validate in your specific matrix.

What it means: Applications list the primary experimental workflows this product has been used for: Cell-Free DNA Isolation, Nucleic Acid Isolation.

Why it matters:

• Cell-Free DNA Isolation: this product can directly support this workflow based on its surface chemistry and particle properties.
• Nucleic Acid Isolation: this product can directly support this workflow based on its surface chemistry and particle properties.

How to interpret here: This product is suited for the listed applications. The most relevant for this product are Cell-Free DNA Isolation, Nucleic Acid Isolation. Review the application-specific protocol in the Documents section before beginning workflow development.

Tip: Application suitability depends on specific experimental conditions (buffer, sample matrix, target concentration). Always validate at pilot scale before full assay development.