Non-formalin Fixation for Biomolecule Integrity

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Solution Overview

Problem

Current methods for stabilizing biological samples, especially non-formalin-fixed samples, fail to effectively preserve the integrity of biomolecules such as RNA and DNA for molecular analysis, leading to degradation and incomplete extraction due to the use of crosslinking agents like formaldehyde, which are also toxic and unsuitable for molecular biology processes.

Innovation Solution

A method involving the use of non-formalin fixation techniques, such as those using Carnoy's, Methacarn, Umfix, Finefix, or PAXgene Tissue Kit, followed by quick staining and de-waxing, allows for the visualization and isolation of biomolecules by mounting the sample on a support, treating with a sample treatment agent, staining for a short duration, and then isolating RNA from the target cells or tissue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If formalin-based crosslinking fixation is used to stabilize biological samples, then morphological preservation is improved, but biomolecule integrity and extractability deteriorate

Engineering Contradiction:
Improvemorphological preservationVSAvoidbiomolecule integrity
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent removes formalin and other crosslinking agents from the fixation process, extracting the harmful element that causes biomolecule degradation. Instead, it uses alternative fixatives that do not crosslink proteins, thereby preserving biomolecule integrity while still achieving morphological stabilization.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical parameters of the fixation process by switching from crosslinking agents (formalin) to non-crosslinking alternatives (such as alcohol-based fixatives or protease-based systems). This parameter change eliminates the harmful crosslinking reaction while maintaining the stabilizing function needed for morphological preservation.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If formalin fixation is applied to stabilize biomolecules, then sample stabilization is improved, but extractability of nucleic acids and proteins deteriorates

Engineering Contradiction:
Improvesample stabilizationVSAvoidextractability of biomolecules
Core Design Contradiction:
Stability of the object's compositionVSLoss of substance

Solution Approach 1:

The patent extracts and removes formalin from the fixation protocol, eliminating the substance that prevents biomolecule extraction. By using alternative non-crosslinking fixatives, the method achieves stabilization without creating a barrier to subsequent extraction processes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces intermediary substances (alternative fixatives that do not crosslink) that mediate between the need for stabilization and the need for extractability. These intermediaries provide the stabilizing function without the harmful crosslinking effect that blocks extraction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If crosslinking stabilizers like formalin are used, then tissue preservation is improved, but toxicity and suitability for molecular biology deteriorate

Engineering Contradiction:
Improvetissue preservationVSAvoidtoxicity
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful crosslinking mechanism into a beneficial non-crosslinking alternative. By replacing formalin with fixatives that work through different mechanisms (such as protein precipitation or enzymatic stabilization), it maintains tissue preservation while eliminating toxicity and molecular biology incompatibility.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical mechanism parameters of tissue preservation from crosslinking to non-crosslinking methods. This parameter change maintains the stabilizing effect on tissue morphology while removing the harmful toxicity and incompatibility with molecular biology techniques.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If rapid staining is performed to minimize RNA degradation, then RNA integrity is improved, but staining quality and target cell identification deteriorate

Engineering Contradiction:
ImproveRNA integrityVSAvoidtarget cell identification
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent optimizes the staining parameters by using highly sensitive stains that require minimal incubation time. By changing the stain concentration, type, or application method, it achieves sufficient target cell identification within seconds to minutes, thereby preserving RNA integrity while maintaining detection capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces prolonged mechanical staining processes with rapid alternative staining methods. This substitution maintains the ability to identify target cells while significantly reducing the time the RNA is exposed to potential degradation, thereby preserving RNA integrity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables the preservation of biomolecules in a life-like state, allowing for effective extraction and analysis of RNA and DNA from non-formalin-fixed samples, maintaining their integrity and enabling downstream applications like quantitative RT-PCR, while avoiding the toxicity and limitations of formalin-based methods.

Implementation Method 1

the biomolecule status of a biological material taken out from its natural environment alters increasingly, the longer the elapsed time between the sample collection and its analysis. In particular the ribonucleic acids (RNA) degrade quickly due to ubiquitous RNases.

Methodology Applied
Scientific EffectChemical stabilization:

Implementation Method 2

staining at least one part of the fixed biological sample mounted on at least one support for not more than 60 seconds with at least one cell or tissue staining agent

Methodology Applied
Scientific EffectStaining:

Implementation Method 3

isolating the biomolecules from the separated cells or tissue

Methodology Applied
Scientific EffectExtraction:

Data Source

PatentEP2580348B1Method for determination of target cells or tissue for extraction of biomolecules from non-formalin-fixed biological samples
Publication Date: 2018.04.25 QIAGEN GMBH
  • EP2580348B1 patent drawingFigure 1~2
  • EP2580348B1 patent drawingFigure 3~4
  • EP2580348B1 patent drawingFigure 5~6

AI summary

The present invention relates to a method for determination of target cells or tissue for isolating or extracting biomolecules from fixed biological samples, the preparation of a sample in a method for extracting, isolating and/or purifying biomolecules from a fixed biological sample as well as to a kit for visualizing target cells or tissue in a fixed biological sample for extracting, isolating and/or purifying biomolecules from said target cells or tissue.