Pig-A Gene Mutation Assay Using Paramagnetic Bead Enrichment

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Solution Overview

Problem

Current methods for quantifying Pig-A gene mutations in peripheral blood samples are time-consuming and result in suboptimal numbers of cells being analyzed, leading to unreliable estimates of mutation frequency, especially in individuals not exposed to potent mutagens.

Innovation Solution

A method involving a three-color labeling approach with fluorescent reagents to separate and enumerate GPI anchor-deficient erythrocytes and reticulocytes from wild-type cells, using paramagnetic beads and flow cytometry to enrich for mutant phenotype cells, allowing for more precise and rapid measurement of mutant cell frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional methods are used to quantify Pig-A gene mutations, then the analysis can be performed with simple procedures, but the analysis time is excessive and the number of cells analyzed is suboptimal, leading to unreliable estimates

Engineering Contradiction:
Improvemutation frequency estimationVSAvoidanalysis time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The analysis is segmented into distinct phases: enrichment of erythrocytes from whole blood, labeling with fluorescent reagents, magnetic separation of mutant cells, and flow cytometric analysis. This segmentation allows each step to be optimized independently, reducing total analysis time while improving precision through targeted cell enrichment before counting

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Erythrocytes are enriched and mutant cells are pre-separated using paramagnetic beads before the actual counting process. This preliminary action concentrates the rare mutant cells (frequency of 10^-6 to 10^-9) into a smaller volume, allowing rapid and precise analysis of sufficient cell numbers without processing entire blood samples

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If conventional methods are used to quantify Pig-A gene mutations, then the procedures are simple to perform, but the number of cells analyzed is insufficient, leading to unreliable estimates especially in unexposed individuals

Engineering Contradiction:
Improvemutation frequency estimationVSAvoidnumber of cells analyzed per unit time
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

Manual cell counting and sorting methods are replaced with automated flow cytometry equipped with paramagnetic bead separation. This substitution enables rapid analysis of millions of cells per second with automated gating and counting, dramatically increasing productivity while maintaining simple operational procedures

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

Solution Approach 2:

The physical state of cell separation is changed from manual microscopic identification to magnetic property-based separation using paramagnetic beads. This parameter change allows automated detection and sorting of mutant cells based on their magnetic susceptibility, enabling high-throughput analysis of large cell numbers

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If fluorescent reagents are used to label GPI anchor-expressing erythrocytes, then the detection sensitivity is improved, but the complexity of the labeling procedure increases

Engineering Contradiction:
Improvedetection sensitivityVSAvoidlabeling procedure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Fluorescently labeled paramagnetic beads serve dual functions: they provide magnetic separation capability and simultaneous fluorescent labeling for detection. This multi-functionality reduces the number of separate reagents and steps needed, simplifying the overall procedure while maintaining high detection sensitivity through the combined magnetic-fluorescent signal

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

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 enumeration of Pig-A mutant cells with unprecedented precision and speed, capable of interrogating millions of cells, thereby providing more reliable and sensitive detection of mutant phenotypes, even in the absence of potent mutagens.

Implementation Method 1

contacting the enriched erythrocyte sample with a first fluorescent reagent that labels GPI anchor-expressing erythrocytes, but not GPI anchor-deficient erythrocytes, and a second fluorescent reagent that specifically labels platelets

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

separating the enriched erythrocyte sample into a first portion comprising platelets and GPI anchor-expressing erythrocytes and a second portion comprising GPI anchor-deficient erythrocytes

Methodology Applied
Scientific EffectMagnetism: Magnetism

Implementation Method 3

detecting the fluorescent emission and light scatter produced by the GPI anchor-deficient erythrocytes of the second portion labeled with the third fluorescent reagent

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP2643694B1Rapid in vivo gene mutation assay based on the pig-a gene
Publication Date: 2018.01.03 LITRON LABORATORIES LTD
  • EP2643694B1 patent drawingFigure 1
  • EP2643694B1 patent drawingFigure 2
  • EP2643694B1 patent drawingFigure 3

AI summary

The invention relates to methods and kits for the quantitative analy; in vivo mutation frequencies of the Pig-A gene in individuals, particularly using peripheral blood samples of vertebrates.