Hematoxylin Eosin Staining Buffering Carry-Over

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Solution Overview

Problem

The hematoxylin and eosin staining technique faces issues with carry-over of staining reagents and water, leading to dilution, pH changes, and contamination, which negatively impact the performance, stability, and predictability of the staining system, resulting in unpredictable reagent life and inefficiencies.

Innovation Solution

The use of pH-buffered solutions comprising organic acids and polyhydroxy alcohols, applied at specific points in the staining protocol, to stabilize and modify the pH of subsequent reagents, reducing the adverse effects of carry-over and extending the life of staining reagents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If batch format staining with automated stainers is used, then staining efficiency and throughput are improved, but carry-over of reagents and water occurs leading to dilution, pH changes, and contamination

Engineering Contradiction:
Improvestaining throughputVSAvoidcarry-over effects
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A rack washer station with spray nozzles is introduced as an intermediary between slide processing steps. The spray system delivers washing solution to remove carry-over reagents and water from slides before they enter the next staining container, preventing contamination while maintaining batch processing efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Slides are pre-washed in the rack washer station before entering the main staining sequence. This preliminary action removes excess reagents and water from slide surfaces, preventing carry-over dilution and pH changes in subsequent staining solutions while maintaining high throughput

Inventive Principle:
Principle #10Preliminary action

2Reliability

If reagents are changed frequently to address carry-over effects, then staining quality is maintained, but reagent waste and operational complexity increase

Engineering Contradiction:
Improvestaining quality consistencyVSAvoidreagent waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The rack washer acts as a protective intermediary that prevents carry-over from degrading reagent quality. By continuously cleaning slides between processing steps, the system extends reagent usable life without compromising staining consistency, reducing both reagent waste and change frequency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system monitors staining quality parameters and adjusts washing solution delivery accordingly. This feedback mechanism ensures staining consistency is maintained while optimizing reagent usage, allowing extended reagent life without quality degradation

Inventive Principle:
Principle #23Feedback

3Productivity

If racks carrying multiple slides are used, then processing capacity is improved, but carry-over effects are amplified due to increased surface area for reagent adherence

Engineering Contradiction:
Improveslides processed per rackVSAvoidcumulative carry-over
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The rack washer station provides intermediary cleaning for all slides in the rack simultaneously. The spray system addresses cumulative carry-over from multiple slides, preventing amplified contamination effects while maintaining the productivity benefits of batch rack processing

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The carry-over problem is extracted and addressed separately from the main staining process. The rack washer removes accumulated reagents and water from all slides before they enter the staining sequence, isolating the carry-over issue and allowing uninterrupted high-capacity processing

Inventive Principle:
Principle #2Taking out (Extraction)

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 minimizes the impact of carry-over, maintains reagent stability, and allows for consistent staining quality, reducing the frequency of reagent changes and enhancing the capacity to process slides without compromising staining performance.

Implementation Method 1

The use of pH-buffered solutions comprising organic acids and polyhydroxy alcohols, applied at specific points in the staining protocol, to stabilize and modify the pH of subsequent reagents

Methodology Applied
Scientific EffectpH buffering:

Data Source

PatentEP3264095B1Kit for hematoxylin and eosin staining
Publication Date: 2020.08.12 LEICA BIOSYSTEMS RICHMOND INC
  • EP3264095B1 patent drawingFigure 1
  • EP3264095B1 patent drawingFigure 2
  • EP3264095B1 patent drawingFigure 3

AI summary

The present invention provide for solutions of a defined composition useful in a staining protocol, such as a hematoxylin and eosin staining protocol, when used at certain points of the staining protocol. The formulations of these defined solutions are such that carry-over of the solutions will not negatively impact, or preferably, will stabilize or favorably modify staining reagent solutions coming in contact with the solutions. In certain embodiments of the invention, solutions are buffered to maintain a specific pH that when carried-over-such as carried-over into hematoxylin-will not significantly influence the pH of the next staining reagent.