Water-Soluble Tissue Clearing for Transparency Without Fluorescence Loss
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Solution Overview
Problem
Conventional methods for rendering tissues transparent face issues such as the use of hazardous organic solvents, lengthy processing times, insufficient transparency, tissue swelling, and fluorescence signal attenuation, limiting observation depth and accuracy.
Innovation Solution
A method involving immersion of tissues in a water-soluble solvent mixture of 2,2′-thiodiethanol, glycerol, and a nonionic organoiodine compound aqueous solution, with specific volume ratios, to achieve a refractive index of 1.4 to 1.7, ensuring transparency without harmful solvents and maintaining fluorescence signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional transparentization methods using organic solvents (e.g., tetrahydrofuran, dichloromethane) are used, then transparency is achieved, but hazardous effects occur including carcinogenicity, flammability, and tissue hardening
Solution Approach 1:
The patent changes the chemical composition parameters of the transparentization reagent by formulating a water-soluble solution containing 2,2′-thiodiethanol (10-80 vol%), glycerol (10-40 vol%), and sucrose (10-40 vol%), replacing hazardous organic solvents with a safe aqueous mixture that achieves the same transparency effect without carcinogenicity or flammability
Solution Approach 2:
The patent creates a composite transparentization reagent by combining multiple water-soluble components (2,2′-thiodiethanol, glycerol, and sucrose) in specific proportions to achieve both transparency and safety, where each component contributes specific properties that together resolve the contradiction between transparency and harmful effects
2Shape
If dehydration process is applied to achieve transparency, then transparency is improved, but fluorescence signal disappears or attenuates
Solution Approach 1:
The patent changes the chemical environment parameters by using a water-soluble reagent system that does not require dehydration, thereby maintaining the fluorescence signal while achieving transparency through refractive index matching instead of water removal
Solution Approach 2:
The patent introduces water-soluble components (2,2′-thiodiethanol, glycerol, sucrose) as intermediary substances that mediate the transparentization process without causing fluorescence attenuation, acting as a bridge between the tissue and the imaging system while preserving optical properties
3Shape
If Scale method using high concentration urea is used, then transparency is achieved, but processing time becomes excessively long (on the order of 2 weeks)
Solution Approach 1:
The patent changes the reagent composition parameters by using 2,2′-thiodiethanol combined with glycerol and sucrose in optimized proportions, which significantly accelerates the transparentization process compared to high-concentration urea methods, reducing processing time from weeks to days while maintaining transparency quality
4Shape
If 2,2′-thiodiethanol is used at high concentration (80-85% or more) to achieve transparency, then transparency is improved, but fluorescence signal of fluorescent proteins disappears or attenuates
Solution Approach 1:
The patent creates a composite reagent system combining 2,2′-thiodiethanol (10-80 vol%) with glycerol (10-40 vol%) and sucrose (10-40 vol%), where the synergistic effect of these components achieves transparency at lower 2,2′-thiodiethanol concentrations than conventional methods, thereby preserving fluorescence signals
Solution Approach 2:
The patent optimizes the concentration parameters of 2,2′-thiodiethanol by formulating it at 10-80 vol% rather than high concentrations (80-85% or more), and combines it with glycerol and sucrose to achieve the desired transparency effect at safer, fluorescence-preserving concentrations
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 safe, efficient, and high-quality tissue transparency, allowing for deeper observation and retention of fluorescence signals, suitable for various organs, including those up to 2 cm thick, without causing swelling or weakening.
Implementation Method 1
immersing the tissue in a water-soluble solvent having a refractive index of 1.4 to 1.7
Data Source
AI summary
A method for rendering tissue transparent, comprising a procedure of immersing the tissue in a water-soluble solvent comprising 2,2′-thiodiethanol and at least one of glycerol and a nonionic organoiodine compound is provided as a technique capable of sufficiently rendering various organs transparent without causing their changes by a simple operation without using any poisonous or dangerous organic solvent. In the method for rendering tissue transparent, a mixed solvent of 2,2′-thiodiethanol, glycerol, and a nonionic organoiodine compound aqueous solution is preferably used as the water-soluble solvent.