Disk Epitachophoresis Volume Coupling for Large-Sample Focusing

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Solution Overview

Problem

Conventional electrophoresis devices and methods are limited to small sample volumes, making the analysis of large biological samples, such as nucleic acids from blood and plasma, difficult, and there is a need for improved methods to concentrate and separate components efficiently.

Innovation Solution

The use of epitachophoresis devices with a concentric or polygonal disk architecture allows for electromigration in two dimensions, focusing samples into a smaller volume and increasing concentration through a circular arrangement with varying cross-sectional areas, utilizing electrolytes with different electrophoretic mobilities to separate and concentrate components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional capillary or microfluidic channel designs are used for ITP, then separation and concentration of ionic analytes can be achieved, but the sample volume handling is limited to small volumes (μl scale)

Engineering Contradiction:
Improvesample volume handling capacityVSAvoiddevice architecture complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent transitions from conventional one-dimensional capillary electrophoresis to two-dimensional epitachophoresis using a circular disk geometry. The sample migrates radially outward from the center well through concentric zones of different electrolytes, enabling large volume handling (milliliter scale) while maintaining separation efficiency. This dimensional change allows bulk sample processing without requiring complex multi-channel arrangements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If electrophoresis is performed in a single dimension along a single plane, then the process is simple to implement, but the sample concentration and separation efficiency are limited

Engineering Contradiction:
Improvesample concentration efficiencyVSAvoidelectromigration dimensionality
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention implements two-dimensional electromigration by combining radial migration (first dimension) with vertical migration through a conical channel (second dimension). The sample is focused radially outward in the first dimension, then concentrated vertically in the conical section, achieving high concentration factors (up to 1000-fold) while maintaining a relatively simple disk-based device structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The conical channel is nested within the circular disk structure, creating a compact two-dimensional concentration system. The conical section is positioned at the periphery of the disk, allowing sequential processing steps (radial migration followed by vertical concentration) within a single integrated device without requiring multiple separate components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Measurement precision

If the first electrolyte is discontinuous with the second electrolyte, then sharp moving boundaries and focused zones are achieved, but the device structure becomes more complex

Engineering Contradiction:
Improvezone boundary sharpnessVSAvoidelectrolyte configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates local discontinuities in electrolyte composition at specific radial positions within the circular channel. The first electrolyte zone and second electrolyte zone are separated by a distinct interface, with each zone having different ionic compositions optimized for specific functions (sample loading and focusing vs. concentration and collection). This localized electrolyte differentiation achieves sharp zone boundaries without requiring complete system complexity.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables efficient concentration and separation of large volumes of biological samples, allowing for higher sample concentration and improved analysis, with concentration factors ranging from 2 to 1000, and facilitates integration with other analytical systems like LC, CE, NMR, and mass spectrometry.

Implementation Method 1

electrophoresis generally involves the movement of an electrically-charged substance (e.g., molecules or ions) under the influence of an electric field

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Implementation Method 2

EM may then continue in a second dimension... Electromigration of a sample may first occur in a first dimension along a single plane

Methodology Applied
Scientific EffectElectromigration:

Implementation Method 3

The balance of electromigration and diffusion at the zone boundaries in ITP typically results in sharp moving boundaries

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP4327090B1Device for volume coupling in epitachophoresis
Publication Date: 2026.01.21 F HOFFMANN LA ROCHE & CO AG
  • EP4327090B1 patent drawingFigure 1
  • EP4327090B1 patent drawingFigure 2A~2B
  • EP4327090B1 patent drawingFigure 3

AI summary

Epitachophoresis (ETP) methods and devices that improve concentrating samples and/or separating components of samples. ETP methods and devices allow for electromigration in two dimensions. Electromigration of a sample may first occur in a first dimension along a single plane. Electromigration may then continue in a second dimension, which may be different from the first dimension. The volume where the electromigration occurs may significantly reduce from the first dimension to the second dimension. This smaller dimension may allow for increased concentration of samples or improved separation of components of a sample.