Microfluidic Channel Cleaning Liquid for Adsorption Recovery

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Solution Overview

Problem

Microchips used in electrophoresis face performance degradation due to adsorption of components like proteins and DNA, which is not adequately addressed by conventional cleaning methods, leading to inconsistent separation characteristics and reduced reuse potential.

Innovation Solution

A polar organic solvent-based cleaning liquid, with a buffer solution pH of 8 to 10 and containing a protein denaturant, is used to effectively remove adsorbed components from the microchip surfaces, improving performance recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional water-based cleaning methods are used, then the cleaning process is simple, but the performance recovery of the microchip is insufficient due to adsorption of proteins and other components

Engineering Contradiction:

Improveperformance recoveryVSAvoidcleaning process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the chemical parameters of the cleaning liquid by using organic solvents with specific solubility characteristics (at least the same volume solubility in water at 25°C) and controlling buffer pH (8-10) with protein denaturants (3-8M concentration). These parameter changes enable effective removal of adsorbed proteins and other components from the microchip channel surfaces, significantly improving performance recovery compared to conventional water-based cleaning methods.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the microchip is reused after conventional cleaning, then running cost is reduced, but separation characteristics change over time due to incomplete removal of adsorbed components

Engineering Contradiction:

Improvereuse frequencyVSAvoidseparation characteristics

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent employs specific parameter changes in the cleaning liquid composition - organic solvents with defined solubility, buffer pH 8-10, and protein denaturants at 3-8M concentration - to thoroughly remove adsorbed proteins and other components. This comprehensive cleaning maintains consistent separation characteristics across multiple uses, enabling high-frequency reuse without degradation of performance stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional mechanical/physical cleaning approaches with chemical cleaning mechanisms. By using organic solvents and protein denaturants, the cleaning process chemically disrupts and removes adsorbed components that mechanical cleaning cannot effectively eliminate, thereby maintaining separation characteristics over repeated use cycles.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If purification or dilution of crude samples is performed, then adsorption on channel surface is reduced, but simplicity of operation is reduced due to additional steps

Engineering Contradiction:

Improveadsorption on channel surfaceVSAvoidoperational simplicity

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent applies preliminary action by cleaning the microchip channel surface before sample analysis to remove potential adsorption sites. By pre-cleaning the surface with organic solvent-based cleaning liquid, the channel is prepared in a state that minimizes subsequent adsorption of sample components, eliminating the need for sample purification or dilution steps and maintaining operational simplicity.

Inventive Principle:

Principle #10Preliminary action

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 proposed cleaning method significantly recovers microchip performance by reducing adsorption and maintaining separation characteristics, allowing for repeated use without significant loss of efficiency.

Implementation Method 1

cleaning a channel that is formed in the microfluidic device, has a surface having a polymer coating, and has been brought into contact with a sample containing nucleic acid and/or protein, by bringing the channel into contact with a cleaning liquid comprised only of an organic solvent having solubility in at least the same volume of water at 25° C.

Methodology Applied

Scientific EffectSolvation: Solvation

Implementation Method 2

the buffer solution further contains 3 to 8M of a protein denaturant

Methodology Applied

Scientific EffectProtein denaturation:

Data Source

PatentUS9303239B2Method for cleaning microfluidic device and cleaning liquid

Publication Date: 2016.04.05 SHIMADZU CORP

AI summary

The present invention provides a cleaning method by which the performance of a microchip can be recovered and a cleaning liquid. A method for cleaning a microfluidic device comprising: cleaning a channel that is formed in the microfluidic device, has a surface having a polymer coating, and has been brought into contact with a sample containing nucleic acid and/or protein, by bringing the channel into contact with a cleaning liquid comprised only of an organic solvent having solubility in at least the same volume of water at 25° C., or a cleaning liquid containing 50 vol % or more of the organic solvent in a buffer solution. The method wherein the buffer solution has a pH of 8 to 10. The method wherein the buffer solution further contains 3 to 8M of a protein denaturant. The method wherein the buffer solution has a pH of 2 to 4.