Viability Staining Method Using Fluorescent Dye and Quencher

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Solution Overview

Problem

Current methods for detecting microbial contamination in industries like food, water, and pharmaceuticals are slow and lack specificity, requiring days to determine the presence and viability of microbial cells, which can lead to product quarantines and increased costs.

Innovation Solution

A method using a membrane permeable nucleic acid binding fluorescent dye and a membrane impermeable quencher to selectively label and differentiate viable and non-viable cells, allowing for rapid detection of viable microorganisms through fluorescence emission analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional cell culture methods are used to assess microbial contamination, then the detection is thorough and accurate, but the testing time is extended to several days

Engineering Contradiction:
Improvedetection accuracyVSAvoidtesting time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces traditional mechanical cell culture methods with a fluorescence-based optical detection system. The method uses fluorescent dyes that bind to nucleic acids in viable cells, allowing rapid visualization and counting under a fluorescence microscope within hours rather than days, while maintaining detection accuracy.

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

Solution Approach 2:

The patent employs fluorescent dyes that emit specific wavelengths of light when bound to nucleic acids in viable cells. This color/fluorescence change enables rapid differentiation between viable and non-viable cells through fluorescence microscopy, providing quick results without lengthy culture periods.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If nucleic acid binding stains are used for mammalian cells, then the staining works well for mammalian cells, but the staining effectiveness decreases for microbial cells due to lower nucleic acid content

Engineering Contradiction:
Improvestaining effectivenessVSAvoidapplicability to different cell types
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent modifies the staining parameters by using fluorescent dyes with high affinity for nucleic acids and optimizing the staining protocol to work with the lower nucleic acid content in microbial cells. The method adjusts dye concentration and exposure time to ensure effective staining of both mammalian and microbial cells despite their different nucleic acid quantities.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent develops a universal staining method that can effectively stain both mammalian cells and microbial cells using the same fluorescent nucleic acid binding dyes. The protocol is designed to be adaptable across different cell types by adjusting parameters such as dye concentration and incubation time, making it versatile for various applications.

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

3Productivity

If rapid detection methods are implemented, then the quarantine time is reduced and productivity increases, but the detection precision and reliability may be compromised

Engineering Contradiction:
Improvedetection speedVSAvoiddetection reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces time-consuming mechanical culture methods with rapid fluorescence-based optical detection. The fluorescent dyes provide immediate visualization of viable cells, enabling results within hours while maintaining reliability through the specific binding of dyes to nucleic acids in metabolically active cells.

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

Solution Approach 2:

The patent uses fluorescent dyes as intermediaries that specifically bind to nucleic acids in viable cells. This intermediary approach allows rapid detection by providing a visible signal through fluorescence microscopy, enabling quick results without compromising reliability due to the specific and selective nature of the dye-nucleic acid interaction.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables rapid detection of viable microbial cells within hours, reducing quarantine times and improving the efficiency of microbial contamination testing, while maintaining the viability of cells for further identification.

Implementation Method 1

a membrane permeable nucleic acid binding fluorescent dye under conditions that permit the fluorescent dye to permeate both viable and non-viable cells

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

a membrane impermeable nucleic acid binding fluorescence quencher capable of quenching fluorescence produced by the fluorescent dye

Methodology Applied
Scientific EffectFluorescence quenching: Absorption (EM radiation)

Data Source

PatentEP2769218B1Viability staining method
Publication Date: 2016.08.10 CHARLES RIVER LABORATORIES INC
  • EP2769218B1 patent drawingFigure 1A
  • EP2769218B1 patent drawingFigure 1B
  • EP2769218B1 patent drawingFigure 1C

AI summary

The invention relates to a method of detecting viable cells in a cell sample, using a membrane permeable fluorescent label that permeates both viable and non- viable cells and a membrane impermeant quencher that selectively permeates non-viable cells.