Antigen Analysis Microchip Using Magnetic Capture and Optical Counting
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Solution Overview
Problem
Existing antigen analysis methods using microchips face challenges with non-uniform fluid movement patterns due to capillary forces, leading to reduced sensitivity and accuracy in antigen-antibody reactions, especially for low antigen concentrations, and require sensitive sensor calibration, which can increase complexity and cost.
Innovation Solution
A fluid drag and magnetism-based microchip using magnetic particles and beads with countable sizes forms immune complexes, allowing for optical counting and capturing these complexes in wells, combined with a digital inline microscope for rapid and accurate quantitative analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If capillary force is used as the main driving force for fluid movement in microchannels, then the microchip structure is simple and passive, but the fluid movement pattern becomes irregular and nonuniform, reducing antigen-antibody reaction efficiency and detection sensitivity
Solution Approach 1:
A magnetic field is introduced as an intermediary force to control the movement of magnetic particles carrying antibodies. The magnetic field acts as a mediator between the driving force and the assay sample, enabling uniform fluid movement and improved antigen-antibody reaction efficiency while maintaining the simplicity of the microchip structure.
Solution Approach 2:
The patent changes the physical parameter of fluid driving force from passive capillary action to active magnetic field control. By applying an external magnetic field, the movement characteristics of the fluid and magnetic particles are altered to achieve uniform flow patterns and enhanced detection sensitivity.
2Measurement precision
If fluorescently labeled probes are used for quantitative analysis, then detection sensitivity is improved, but sensor calibration complexity and cost increase
Solution Approach 1:
The patent extracts and removes the fluorescent labeling step from the assay system. Instead of using fluorescently labeled probes that require complex calibration, the invention uses unlabeled magnetic particles combined with a magnetic field for detection, thereby eliminating the need for sensitive sensor calibration while maintaining detection sensitivity.
Solution Approach 2:
The patent replaces the optical detection system (fluorescence detection requiring calibration) with a magnetic field-based control and detection system. The magnetic field provides both the driving force for particle movement and the mechanism for detecting immune complexes, eliminating the need for complex optical sensor calibration.
3Measurement precision
If fluorescent probes are used for antigen detection, then target antigen can be detected, but errors occur from probes not bound to antigen or floating without immobilization
Solution Approach 1:
Magnetic particles serve as an intermediary carrier for antibodies. These magnetic particles can be precisely controlled and positioned using an external magnetic field, ensuring that only antigen-bound complexes are detected. This eliminates errors from unbound or floating probes while maintaining reliable antigen detection.
Solution Approach 2:
The patent applies a magnetic field that can dynamically control the position and movement of magnetic particles. By oscillating or varying the magnetic field, unbound particles can be separated from bound complexes, improving detection accuracy by ensuring only specific immune complexes are counted.
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
The method provides highly sensitive and accurate quantitative analysis of antigens by effectively capturing and counting immune complexes, reducing errors from fluorescence probes and improving detection sensitivity without the need for fluorescent labeling.
Implementation Method 1
using magnetic particles and beads with countable sizes that form immune complexes via a target antigen
Implementation Method 2
a fluid drag and magnetism-based microchip for quantitatively analyzing an antigen
Data Source
AI summary
A method of quantitatively analyzing an antigen includes a step of mixing an assay sample comprising a target antigen, magnetic particles on which a first antibody subjected to an antigen-antibody reaction with the target antigen is immobilized, and beads on which a second antibody different from the first antibody is immobilized; a step of adding dropwise the mixed assay sample to a microchip for quantitatively analyzing an antigen; a step of introducing the microchip into a digital inline microscope-based detector comprising a magnetic force applicator and applying magnetism to the magnetic force applicator; and a step of detecting the beads using images acquired in the detector to count the number of the target antigens.