FFPE Tissue DNA/RNA Extraction With Single-Buffer Lysis

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Solution Overview

Problem

The analysis of nucleic acids from formalin-fixed, paraffin-embedded tissue (FFPET) samples is challenging due to their poor quality and quantity, which restricts their utilization in gene expression profiling studies, and existing extraction methods are complex and labor-intensive.

Innovation Solution

A simplified, semi- or fully-automated method using a single lysis solution at a single temperature to extract nucleic acids from FFPE samples, comprising sodium salt, buffer, chelating agent, magnesium salt, and detergent, which results in high yield and PCR-amplifiable quality nucleic acids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple steps are used for nucleic acid extraction from FFPET samples (deparaffinization, protease digestion, cross-link reversal, solid phase purification), then extraction completeness is improved, but process complexity and labor intensity increase

Engineering Contradiction:
Improveextraction completenessVSAvoidprocess complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent combines multiple extraction steps (deparaffinization, lysis, and purification) into a single integrated buffer solution. The buffer contains ingredients that simultaneously perform deparaffinization, cell lysis, and nucleic acid purification, eliminating the need for separate processing steps and significantly reducing procedural complexity while maintaining extraction effectiveness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single buffer solution is designed to perform multiple functions simultaneously: it acts as a deparaffinizing agent, a lysis buffer, and a purification reagent. This multi-functional approach allows one solution to replace multiple specialized reagents and steps, directly addressing the contradiction between extraction completeness and process complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Quantity of substance

If multiple steps and reagents are used for nucleic acid extraction from FFPET samples, then extraction completeness is improved, but hands-on time and labor increase

Engineering Contradiction:
Improveextraction completenessVSAvoidhands-on time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

By merging deparaffinization, lysis, and purification into a single buffer application step, the patent dramatically reduces the time researchers must spend manually processing samples. Instead of sequentially performing multiple operations, users simply apply one buffer and incubate, cutting hands-on time while preserving extraction completeness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The buffer is pre-formulated with all necessary components (deparaffinizing agents, lysis enzymes, and purification chemicals) in optimal concentrations and combinations. This preliminary preparation of a ready-to-use single solution eliminates the need for users to prepare multiple reagents or perform multiple handling steps, reducing both time and labor requirements.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If RNA is purified from FFPET samples using conventional methods, then RNA can be obtained, but RNA quality is degraded and fragmented

Engineering Contradiction:
ImproveRNA recoverabilityVSAvoidRNA quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent modifies the chemical parameters of the extraction buffer, specifically using a non-ionic detergent system that operates under conditions preserving RNA integrity. The buffer's pH, ionic strength, and chemical composition are optimized to prevent RNA degradation and fragmentation while still effectively removing paraffin and lysing cells, thus improving both recoverability and quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The method employs a single-use disposable buffer solution that is discarded after one application, eliminating the need for multiple handling steps and intermediate storage. This approach prevents RNA degradation that can occur during prolonged processing or multiple transfers, maintaining RNA quality while ensuring complete extraction.

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

4Stability of the object's composition

If formalin fixation is used for tissue preservation, then tissue stability is improved, but nucleic acid quality deteriorates due to cross-linking and degradation

Engineering Contradiction:
Improvetissue stabilityVSAvoidnucleic acid quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent converts the harmful effect of formalin cross-linking into a beneficial process by incorporating specific buffer ingredients that selectively reverse cross-links only in the regions containing nucleic acids, while leaving the rest of the tissue structure intact. This allows the tissue to remain stable for histological purposes while releasing high-quality nucleic acids for molecular analysis.

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

Solution Approach 2:

The buffer solution acts locally and selectively on different tissue components: it reverses formalin cross-links specifically at nucleic acid locations while maintaining tissue morphology elsewhere. This localized action preserves tissue stability for pathological examination while simultaneously improving nucleic acid quality for extraction.

Inventive Principle:
Principle #3Local quality

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 achieves rapid, efficient extraction of high-quality nucleic acids suitable for PCR amplification, reducing hands-on time and labor, and is applicable to various tissue samples, including FFPE, fresh, and frozen tissues.

Implementation Method 1

lysis of preserved sample (protease digestion)

Methodology Applied
Scientific EffectChemical lysis:

Implementation Method 2

removal of paraffin (deparaffinization)

Methodology Applied
Scientific EffectDissolution:

Implementation Method 3

chelating agent

Methodology Applied
Scientific EffectChelation:

Implementation Method 4

detergent

Methodology Applied
Scientific EffectSolubilization:

Implementation Method 5

buffer

Methodology Applied
Scientific EffectpH buffering:

Data Source

PatentEP3705582B1Compositions and methods for DNA and RNA extraction from tissue samples
Publication Date: 2025.09.03 CEPHEID INC
  • EP3705582B1 patent drawingFigure 1
  • EP3705582B1 patent drawingFigure 2A~2B
  • EP3705582B1 patent drawingFigure 2C

AI summary

Methods and reagents are provided for the rapid extraction of nucleic acids from a cell or tissue sample. In certain embodiments the sample comprises a formalin fixed paraffin embedded sample (e.g., a FFPET sample), or a fine needle aspirate and/or a cell/tissue smear. In some embodiments, the methods comprise incubating one or more sections of said tissue sample in a lysis solution comprising a buffer sufficient to maintain the pH of said solution at a pH ranging from about pH 4 to about pH 9; a chaotropic agent; a chelating agent; and a detergent; where the incubating is at a temperature ranging from about 50°C to about 100°C; and recovering the nucleic acid from said lysis solution.