Lyophilized magnetic beads for DNA/RNA extraction in microfluidic cartridges
How freeze-dried magnetic particles solve the liquid handling, cold-chain, and aggregation problems that stand between magnetic bead purification and truly integrated point-of-care cartridges.
Building a truly integrated sample-to-answer diagnostic cartridge means solving one of the hardest sample preparation problems in molecular diagnostics: getting magnetic particles — typically supplied as a liquid suspension — reliably inside a sealed microfluidic device, stable at ambient temperature, and ready to perform on demand.
Magnetic bead-based nucleic acid purification is the accepted method for automated, centrifuge-free sample preparation in microfluidic systems. The bind-wash-elute workflow is well-established and compatible with a wide range of cartridge architectures. The challenge is not the chemistry — it is the format.
Liquid magnetic particle suspensions are difficult to pre-load into sealed cartridges. They require refrigeration or freezing, which limits ambient-temperature distribution and storage. And without the right formulation, lyophilization of magnetic particles causes aggregation, loss of surface modification integrity, and reduced DNA/RNA binding capacity — defeating the purpose of the process.
Why liquid magnetic particle suspensions don't fit sealed cartridges
What a lyophilized magnetic bead has to preserve
To be usable in a real cartridge, a freeze-dried magnetic bead has to arrive at the assay with all the properties of the original liquid suspension intact. That means meeting a set of demanding criteria simultaneously:
No particle aggregation during lyophilization or upon reconstitution — a well-dispersed suspension every time.
Surface chemistry integrity — the silica or functional coating that binds DNA and RNA must be fully preserved.
Particle size distribution maintained through the freeze-drying cycle.
Concentration reproducibility batch-to-batch, at manufacturing scale.
Instant, complete rehydration compatible with fast-moving microfluidic flow.
Long-term stability at ambient temperature — no cold chain.
Meeting all of these criteria at once is not achievable with a generic lyoprotectant panel. It requires an excipient formulation engineered specifically for magnetic particles.
What EVIK™ MagSpheres are
EVIK™ MagSpheres are preformulated, lyophilized beads containing magnetic micro- or nanoparticles engineered for nucleic acid extraction and purification. Rather than integrating magnetic particle suspensions — which introduce liquid handling challenges, cold-chain requirements, and aggregation risks into cartridge manufacturing — EVIK™ MagSpheres deliver the same particles in a dry, stable, ready-to-integrate bead format.
Each bead dissolves instantly upon rehydration, releasing a precisely dosed suspension of magnetic particles with their surface chemistry, DNA/RNA binding capacity, and particle size distribution fully intact. This is achieved through a proprietary lyophilization process developed by Evik Diagnostics, using an optimised excipient composition specifically designed to protect magnetic particles through the freeze-drying cycle and through long-term ambient storage.
The following criteria are what distinguish a truly cartridge-ready lyophilized magnetic bead from a generic freeze-dried particle preparation.
Aggregation prevention
The excipient formulation prevents particle aggregation both during lyophilization and upon reconstitution, delivering a uniform, well-dispersed suspension every time.
Surface modification preserved
The silica or functional surface chemistry of the magnetic particles is fully maintained through the freeze-drying process, preserving the DNA/RNA binding capacity that the extraction step depends on.
Particle size and concentration integrity
Magnetic particle concentration and size distribution remain consistent across large manufacturing runs, batch to batch — critical for IVD developers who need reliable, reproducible performance at commercial scale.
Instant rehydration
The lyobead format provides maximum surface-area-to-volume ratio, enabling rapid, complete reconstitution as soon as buffer contacts the bead — compatible with fast-moving microfluidic flow.
Ambient temperature stability
No cold chain is required for storage or distribution. Beads can be pre-loaded into sealed cartridges and stored at room temperature, ready to perform whenever the cartridge is used.
Cartridge-ready format
Designed specifically for direct integration into microfluidic cartridges, lab-on-chip systems, and sample-to-answer diagnostic platforms — compatible with centrifugal, pressure-driven, and lateral-flow cartridge architectures.
Six performance criteria for a cartridge-ready magnetic bead
EVIK™ MagSpheres are available in customised bead sizes and magnetic particle concentrations to accommodate different extraction and purification volumes, sample types, and cartridge formats.
Whether your workflow requires a small-volume bead for a compact microfluidic channel, a higher particle concentration for challenging sample matrices with low nucleic acid yield, or a specific particle-to-volume ratio to match your bind-wash-elute protocol, Evik Diagnostics can formulate MagSpheres to specification. Standard and custom formats are available for prototyping through to commercial-scale manufacturing.
Configuration for different cartridge formats
Custom plate configurations, excipient combinations, ratios, and full factorial designs are available on request. Contact our team to discuss your formulation requirements.
Where lyophilized magnetic beads are being deployed
Freeze-dried magnetic beads for cartridge integration are being adopted by teams working on:
- Point-of-care diagnostic cartridge developers integrating on-chip nucleic acid extraction
- IVD manufacturers developing sample-to-answer molecular diagnostic systems
- Microfluidic engineers designing lab-on-chip nucleic acid amplification test (NAAT) platforms
- Research teams developing integrated extraction-plus-amplification workflows
- Diagnostic kit developers requiring ambient-stable, cartridge-compatible magnetic bead reagents
- Global health and resource-limited setting programmes requiring cold-chain-free reagents
About the product range. EVIK™ MagSpheres are part of the EVIK™ range of preformulated lyobeads, developed and manufactured by Evik Diagnostics — specialists in freeze-dry bead formulation for molecular diagnostics, built on more than 15 years of expertise.
To request a quote, a datasheet, or to discuss a custom formulation, get in touch with our team .