Electrophoresis (Diagnostic) is a laboratory technique that separates charged biomolecules, such as proteins, hemoglobin, or nucleic acids, by moving them through a gel or capillary medium under an electric field so they can be identified by size and charge. IVD instruments built on this principle detect abnormal protein bands, hemoglobin variants, and DNA fragments for clinical interpretation.
What is Electrophoresis (Diagnostic)?
In vitro diagnostics (IVD) rely on separation science to turn a raw biological sample into a readable result, and diagnostic electrophoresis is one of the oldest separation methods still in wide use. A sample, often serum, whole blood, or an amplified nucleic acid product, is loaded onto a gel or into a buffer-filled capillary. An applied voltage drives charged molecules toward the oppositely charged electrode, and smaller or more highly charged molecules move faster. The result is a pattern of bands or peaks that a technician or the instrument’s software interprets against a reference.
Two formats dominate diagnostic use. Gel electrophoresis, typically agarose or polyacrylamide, is used for serum protein electrophoresis (SPEP), hemoglobin electrophoresis, and Western blot confirmatory testing. Capillary electrophoresis (CE) replaces the slab gel with a narrow capillary tube, giving faster runs, better resolution, and easier automation, which is why most modern hemoglobinopathy screening and fragment-analysis workflows have moved to CE-based platforms.
Why Electrophoresis (Diagnostic) matters in medical device development
A misread electrophoresis result carries direct clinical weight. A missed monoclonal band on an SPEP can delay a myeloma workup; a misclassified hemoglobin variant can send a sickle cell trait carrier down the wrong counseling path. Because the output depends on resolution, migration consistency, and correct peak or band calling, small deviations in reagents, voltage, or software thresholds change the clinical answer.
On the regulatory side, electrophoresis-based instruments are IVD medical devices. Under EU IVDR (Regulation (EU) 2017/746), most fall into risk class B or C, setting the depth of technical documentation and performance evaluation required under Annex XIII. In the US, the FDA reviews these instruments under 21 CFR Part 809, often through the 510(k) pathway, referencing predicates with comparable methods. Weak performance data or gaps in the design history file (DHF) are common reasons submissions stall.
How Electrophoresis (Diagnostic) works
A diagnostic electrophoresis system is built around a small set of core elements, each of which becomes a design input and a verification target:
- Power supply and electrode assembly, which generate and control the electric field.
- Separation medium, either a cast gel or a fused-silica capillary, matched to the analyte class.
- Buffer system, which maintains pH and ionic strength during the run.
- Detection module, commonly UV absorbance, laser-induced fluorescence, or post-run staining with densitometry.
- Interpretation software, which calls bands or peaks, flags abnormal patterns, and generates the report.
Because software increasingly drives clinical interpretation, it falls under IEC 62304 for medical device software lifecycle processes, with algorithm changes treated as design changes requiring re-verification. The instrument is typically qualified to IEC 61010-2-101, the safety standard for IVD laboratory equipment, rather than IEC 60601-1, since it processes a sample rather than connecting to a patient. Usability engineering under IEC 62366-1 covers sample loading and result review, and the quality system sits under ISO 13485 with risk management per ISO 14971.
Common challenges and best practices
Reagent and consumable lot variability is the most persistent source of drift in electrophoresis assays. A new gel or capillary lot can shift migration times enough to affect peak calling if the system isn’t requalified against it, so mature programs build lot-to-lot bridging studies into change control rather than treating reagents as static.
Cross-contamination between runs is another recurring issue in capillary systems, where carryover from a high-concentration sample can create a false low-level peak in the next run. Rinse cycles need to be validated, not assumed. On the software side, teams sometimes validate the peak-calling algorithm once at launch and then update thresholds informally in response to complaints. Any change to interpretation logic is a software change under IEC 62304 and needs documented verification, or it becomes an audit finding.
Good programs also plan analytical performance studies, precision, accuracy, linearity, and interference early enough to satisfy both FDA and IVDR expectations in parallel. Retrofitting a US-only study plan for European documentation late in development is a common source of schedule slip.
How SJML helps with Electrophoresis (Diagnostic)
SJML supports diagnostics and IVD programs across the full development path, from electromechanical and embedded software design through verification and design transfer, with usability engineering and risk management built into the process. Its microfluidics and lab-on-chip experience applies directly to cartridge-based or point-of-care electrophoresis platforms, and in-house electrical safety and reliability testing supports IEC 61010-2-101 qualification. SJML’s QARA team handles IVDR and FDA regulatory strategy, technical file preparation, and performance evaluation planning, along with post-market surveillance once the instrument ships. Manufacturing spans PCBA, cleanroom assembly, and system integration for the finished instrument.
Talk to SJML’s engineering team →
Frequently asked questions
It separates and identifies charged biomolecules in a clinical sample. Common diagnostic uses include serum protein electrophoresis (SPEP) for detecting monoclonal proteins linked to conditions like multiple myeloma, hemoglobin electrophoresis for hemoglobinopathies such as sickle cell disease, and capillary electrophoresis for nucleic acid fragment analysis in molecular diagnostics.
Gel electrophoresis separates molecules across a flat slab of agarose or polyacrylamide and is read visually or by densitometry. Capillary electrophoresis (CE) performs the same separation inside a narrow capillary tube, giving faster runs, higher resolution, and easier automation, which is why most modern diagnostic platforms use CE.
These instruments are regulated as IVD medical devices. Relevant frameworks include EU IVDR (Regulation (EU) 2017/746), FDA 21 CFR Part 809, ISO 13485 for the quality system, ISO 14971 for risk management, IEC 61010-2-101 for equipment safety, and IEC 62304 where software drives result interpretation.
Classification depends on intended use and clinical risk. Under EU IVDR, most electrophoresis-based IVD instruments fall into risk class B or C. Under the FDA framework, comparable devices are typically Class II and reviewed through the 510(k) pathway, referencing a predicate with similar separation and detection technology.
The peak- or band-calling software is treated as medical device software under IEC 62304, with its own lifecycle documentation, verification testing, and change control. Any update to interpretation thresholds or algorithm counts as a design change and requires re-verification before release.
Related terms
- In Vitro Diagnostic (IVD) Device
- Design Verification
- Analytical Performance Evaluation
- Design History File (DHF)
- IEC 62304 Software Lifecycle
