Antigen Retrieval Using Surfactant and Chaotropic Agents

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Solution Overview

Problem

Current antigen retrieval methods for immunostaining, which involve high temperatures, often degrade the cellular morphology of cytology specimens, making it difficult to maintain the integrity of these samples during the process.

Innovation Solution

A two-solution method using a surfactant and a chaotropic agent, such as sodium dodecyl sulfate (SDS) and lithium perchlorate (LiClO4) respectively, to expose protein epitopes without the need for extreme heat, allowing for effective antigen retrieval while preserving cellular morphology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high temperature pretreatment (80°C or greater) is used to retrieve antigen epitopes, then epitope accessibility for immunostaining is improved, but cellular morphology of cytology specimens is degraded

Engineering Contradiction:

Improveepitope accessibilityVSAvoidcellular morphology

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

The patent changes the temperature parameter from high (80°C or greater) to low (below 60°C, preferably room temperature or 37°C) to achieve epitope retrieval while preserving cellular morphology. This parameter change allows the same antigen retrieval function to be achieved without the harmful thermal effects that degrade cytology specimen morphology.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal mechanism (heat) with a chemical mechanism (enzymatic digestion using proteases such as proteinase K, collagenase, or elastase) to achieve epitope retrieval. This substitution eliminates the need for high temperature while maintaining effective antigen exposure for immunostaining.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If high temperature processing is applied to cytology specimens, then antigen retrieval efficiency is improved, but sample integrity is compromised

Engineering Contradiction:

Improveantigen retrieval efficiencyVSAvoidsample integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the temperature parameter from high to low, enabling efficient antigen retrieval through enzymatic action at temperatures that do not compromise sample integrity. This allows cytology specimens to maintain their structural integrity while achieving effective epitope exposure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes thermal processing with enzymatic processing to achieve antigen retrieval. This replacement maintains sample integrity because enzymatic digestion occurs under mild conditions that do not denature or degrade the overall sample structure, unlike high-temperature processing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If conventional antigen retrieval methods are used on cytology specimens, then epitope exposure is enhanced, but cellular structure is damaged

Engineering Contradiction:

Improveepitope exposureVSAvoidcellular structure

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent changes the temperature and time parameters of the retrieval process, using lower temperatures (below 60°C) and controlled enzymatic treatment durations to achieve epitope exposure while preserving cellular structure. This optimized parameter regime prevents structural damage while maintaining retrieval effectiveness.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/thermal disruption method with a selective enzymatic digestion method. The enzymes specifically cleave cross-links and expose epitopes without randomly degrading cellular structures, thereby maintaining structural stability while achieving epitope exposure.

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 method allows for efficient antigen retrieval in cytology samples without degrading cellular morphology, enabling accurate immunostaining and maintaining the integrity of cytological specimens, as demonstrated by optimal immunostaining results at temperatures below 60°C.

Implementation Method 1

a first solution comprising a surfactant

Methodology Applied

Scientific EffectSurfactant action: Surfactant

Implementation Method 2

Overcoming fixation-induced cross-linking allows for target epitopes buried within the tertiary structure of proteins to become accessible

Methodology Applied

Scientific EffectProtein denaturation:

Implementation Method 3

a second solution comprising a chaotropic agent

Methodology Applied

Scientific EffectChaotropic effect:

Data Source

PatentEP2773390B1Methods and compositions for preparing samples for immunostaining

Publication Date: 2020.12.30 TRIPATH IMAGING INC

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AI summary

Compositions and methods for preparing a sample for immunological staining are provided. Compositions include kits comprising a first solution comprising a surfactant and a second solution comprising a chaotropic agent. Methods comprise contacting a sample, such as cells or tissues, with a first solution comprising a surfactant and then contacting the sample with a second solution comprising a chaotropic agent. The method does not require extreme heat for antigen retrieval and therefore, maintains the cellular morphology of the sample.