Tissue Clearing Composition for High-Transparency Fluorescence Imaging

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Solution Overview

Problem

Existing clearing techniques for biological tissues suffer from issues such as fluorescent protein degradation, low transparency, requirement of specialized equipment, complex processes, and high-temperature treatments, making them unsuitable for high-throughput and low-magnification imaging.

Innovation Solution

A composition comprising compounds with delipidation, decoloring, decalcification, refractive index adjustment, and swelling abilities, used in a simple chemical treatment process without specialized equipment, to make biological materials transparent for high-throughput analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If organic solvent-based clearing methods (BABB method) are used to achieve high transparency, then light-transmitting property is improved, but fluorescent protein degradation occurs significantly

Engineering Contradiction:
Improvelight-transmitting propertyVSAvoidfluorescent protein stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the clearing medium by using fructose (a sugar) instead of organic solvents like benzyl benzoate and benzyl alcohol. This parameter change maintains high light transmittance while preserving fluorescent protein stability, as fructose does not cause the degradation that organic solvents do.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a simple, inexpensive clearing solution based on fructose that can be easily prepared and discarded, replacing complex organic solvent systems. This approach prioritizes preserving fluorescent signals over achieving maximum theoretical transparency, accepting good-enough transparency in exchange for signal preservation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Illumination intensity

If electrophoresis-based clearing method (CLARITY method) is used to achieve high transparency while maintaining molecular structure, then transparency and structure preservation are improved, but device complexity and process difficulty increase

Engineering Contradiction:
ImprovetransparencyVSAvoidequipment requirement
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of lipid removal from the complex electrophoresis system and achieves it through simple chemical treatment with fructose. This eliminates the need for specialized electrophoresis equipment while maintaining the ability to clear tissues and preserve molecular structures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The fructose-based clearing solution works autonomously without requiring external power sources or specialized equipment. The chemical agents in the solution perform the clearing function automatically when applied to the tissue, eliminating dependence on complex devices like electrophoresis apparatus.

Inventive Principle:
Principle #25Self-service

3Illumination intensity

If detergent-based clearing methods (PACT, PARS methods) are used to improve transparency, then light-transmitting property is improved, but tissue structure disruption increases

Engineering Contradiction:
Improvelight-transmitting propertyVSAvoidtissue structure integrity
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical nature of the clearing agent from harsh detergents (SDS) to a gentler sugar-based solution (fructose). This parameter change allows effective lipid removal and transparency improvement while maintaining tissue structure integrity, as fructose is less disruptive to biological macromolecules.

Inventive Principle:
Principle #35Parameter changes

4Illumination intensity

If high-temperature treatment with detergent (SWITCH method) is used to achieve transparency, then light-transmitting property is improved, but fluorescent protein degradation increases

Engineering Contradiction:
ImprovetransparencyVSAvoidfluorescent signal stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes both the temperature parameter and chemical composition parameter. Instead of high-temperature detergent treatment, it uses room-temperature or physiological temperature fructose-based solution. This dual parameter change achieves transparency while preserving fluorescent proteins from both thermal and chemical degradation.

Inventive Principle:
Principle #35Parameter changes

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 composition achieves high transparency in biological materials, minimizing fluorescent signal quenching, allowing multiple samples to be imaged simultaneously with minimal tissue structure disruption, and enabling reversible clearing for further analysis.

Implementation Method 1

A composition for preparing a biological material having an excellent light-transmitting property, the composition being a solution containing at least one compound having a delipidation ability

Methodology Applied
Scientific EffectDelipidation:

Implementation Method 2

A composition for preparing a biological material having an excellent light-transmitting property, the composition being a solution containing at least one compound having a decoloring ability

Methodology Applied
Scientific EffectDecoloring:

Implementation Method 3

A composition for preparing a biological material having an excellent light-transmitting property, the composition being a solution containing at least one compound having a decalcification ability

Methodology Applied
Scientific EffectDecalcification:

Implementation Method 4

A composition for preparing a biological material having an excellent light-transmitting property, the composition being a solution containing at least one compound having a refractive index adjusting ability

Methodology Applied
Scientific EffectRefractive index adjustment: Refraction

Implementation Method 5

A composition for preparing a biological material having an excellent light-transmitting property, the composition being a solution containing at least one compound having a swelling ability

Methodology Applied
Scientific EffectSwelling:

Data Source

PatentEP3450953B1Composition for preparing biological material having excellent light transmissivity and use of composition
Publication Date: 2025.11.19 RIKEN CO LTD
  • EP3450953B1 patent drawingFigure 1
  • EP3450953B1 patent drawingFigure 2
  • EP3450953B1 patent drawingFigure 3

AI summary

The present invention relates to a clearing technique which uses a solution containing at least one of a compound having a delipidation ability, a compound having a biochrome decoloring ability, a compound having a decalcification ability, a compound having a refractive index adjusting ability, and a compound having a tissue swelling ability. The clearing technique is suitable for use in high-throughput and low-magnification imaging which involves a simple process.