Lipid Bilayer Membrane Particle Detection via Magnetic Bead Separation

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Solution Overview

Problem

Current methods for detecting lipid bilayer membrane particles, such as extracellular vesicles and circulating tumor cells, face challenges due to the small size and low surface antigen amount, leading to weak fluorescence signals that are often masked by background noise, making it difficult to achieve sufficient detection sensitivity.

Innovation Solution

A method combining lipid staining with a specifically-binding substance, such as an antibody, and a magnetic bead, where the substance is labeled with biotin and the bead with avidin, allows for improved signal-to-noise ratio through flow cytometry or imaging cytometry by measuring fluorescence intensities of different wavelengths and using scattered light intensity information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional fluorescence detection methods are used for lipid bilayer membrane particles, then the detection process is simple, but the fluorescence signal is weak and masked by background noise due to small particle size and low surface antigen amount

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddetection method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines magnetic bead-based separation with fluorescence detection to create a dual-mode detection system. Magnetic beads are conjugated with antibodies that bind to surface antigens on lipid bilayer membrane particles, enabling both magnetic separation and fluorescence detection in a single integrated approach, thereby overcoming the weak signal problem while maintaining operational simplicity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Magnetic beads serve as intermediary carriers that amplify the detection signal. The beads are conjugated with detection antibodies and their magnetic properties enable concentration and isolation of target particles, effectively amplifying the weak fluorescence signal from small particles by accumulating them in a detectable state

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If magnetic beads are used for separation, then the signal-to-noise ratio is improved, but the detection method becomes more complex

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoiddetection method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The magnetic beads perform multiple functions simultaneously: they serve as separation agents for isolating target particles, as signal amplifiers through their magnetic properties, and as carriers for detection antibodies. This multi-functionality reduces the need for separate reagents and steps, thereby improving signal-to-noise ratio without proportionally increasing method complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent utilizes the magnetic property parameter of the beads to enable separation based on magnetic field application. By changing the physical state of the sample through magnetic field application, target particles can be concentrated and isolated, significantly improving signal-to-noise ratio through a single parameter change rather than multiple complex操作步骤

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple detection parameters are measured, then the detection accuracy is improved, but the measurement system becomes more complex

Engineering Contradiction:
Improvedetection accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the detection process into distinct measurement dimensions: magnetic separation based on magnetic properties, fluorescence detection based on optical properties, and scattered light detection based on physical scattering properties. By segmenting these detection parameters into separate measurement channels, the system achieves high detection accuracy through multi-parameter analysis while keeping each individual measurement channel relatively simple

Inventive Principle:
Principle #1Segmentation

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 enhances the detection sensitivity of lipid bilayer membrane particles by separating and detecting them based on dye emission, effectively distinguishing target signals from background noise, even when the surface antigen amount is small.

Implementation Method 1

separating the substance by applying a magnetic field

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

detecting the separated lipid bilayer membrane particles or fragments thereof on the basis of emission of the dye

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3392658B1Method for detecting lipid bilayer membrane particles or fragments thereof
Publication Date: 2021.07.14 NIHON KOHDEN CORP
  • EP3392658B1 patent drawingFigure 1
  • EP3392658B1 patent drawingFigure 2
  • EP3392658B1 patent drawingFigure 3

AI summary

Provided is a means by which a signal-to-noise ratio (S/N ratio) can be improved at the time of detection of lipid bilayer membrane particles (lipid vesicles) in which the amount of a surface antigen is small since the size of the particles is small and/or the amount of the particles existing in a sample is also small. The present application provides, as a means for solving the above-described problem, a detection technique that relates to a method for detecting lipid bilayer membrane particles or fragments thereof having predetermined molecules existing on surfaces in a biological sample collected from a subject, the method including: adding a dye staining a lipid bilayer membrane to the biological sample; adding a substance specifically binding to the predetermined molecules to the biological sample; trapping the substance to separate the lipid bilayer membrane particles or fragments thereof having predetermined molecules existing on surfaces; and detecting the separated lipid bilayer membrane particles or fragments thereof on the basis of emission of the dye.