Guide · Sample Preparation
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 teamto discuss your formulation requirements.
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
Where lyophilized magnetic beads are being deployed
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.