Flow Cytometry Pulse Width Comparison for Doublet Discrimination

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Solution Overview

Problem

Existing flow cytometry systems struggle to accurately distinguish between single particles (singlets) and concatenated particles (doublets, triplets, etc.) due to issues like false positives and false negatives caused by doublets, which affect data quality.

Innovation Solution

A method and system for characterizing particles using two different pulse width techniques to determine differences between first and second pulse width values, comparing these differences to a threshold to classify particles as singlets or concatenated particles, and employing a waveform analysis to measure pulse widths accurately.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional single technique pulse width measurement is used, then the measurement process is simple, but the accuracy of distinguishing singlets from concatenated particles is poor leading to false positives and negatives

Engineering Contradiction:
Improveparticle characterization accuracyVSAvoidmeasurement technique complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pulse width measurement is segmented into two distinct techniques: direct pulse width measurement and derived pulse width measurement (using area/maximum ratio). By dividing the measurement into two independent methods, the system can compare results to distinguish singlets from concatenated particles, thereby improving measurement precision without excessive complexity increase.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the measurement parameter from a single pulse width value to two different pulse width values obtained through different techniques. This parameter change enables better discrimination between particle types by comparing the consistency of measurements across different methods, resolving the contradiction between accuracy and complexity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If manual gating methods are used for particle discrimination, then the system requires prior population gating, but this reduces productivity and increases operation time

Engineering Contradiction:
Improveparticle analysis throughputVSAvoidoperation simplicity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The system performs automatic particle discrimination by comparing direct and derived pulse width values according to predetermined criteria. This self-service approach eliminates the need for manual gating operations, allowing the system to automatically distinguish singlets from concatenated particles, thereby improving productivity while maintaining operational simplicity through automated decision-making.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system establishes predetermined discrimination criteria before analysis begins, setting the threshold for accepting or rejecting particles based on pulse width consistency. This preliminary action enables automatic real-time discrimination during particle flow, eliminating the need for subsequent manual gating and significantly improving throughput.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If doublets and concatenated particles are excluded from analysis, then data quality improves, but the quantity of analyzable particles decreases

Engineering Contradiction:
Improvedata qualityVSAvoidnumber of analyzable particles
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The system uses feedback from the comparison between direct and derived pulse width values to automatically identify and flag concatenated particles. By providing real-time feedback on particle consistency, the system maintains high data quality by excluding only true concatenated particles while preserving singlets for analysis, thus optimizing both reliability and quantity.

Inventive Principle:
Principle #23Feedback

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 effectively distinguishes singlets from concatenated particles, improving data quality by reducing false positives and negatives, and allows for automatic, on-the-fly discrimination without requiring prior population gating, leading to higher yields.

Implementation Method 1

Light that is scattered and/or emitted by the particles from interaction with the one or more excitation light beams is collected and analyzed

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

Light that is scattered and/or emitted by the particles from interaction with the one or more excitation light beams

Methodology Applied
Scientific EffectFluorescence emission: Fluorescence

Data Source

PatentEP4533066B1Particles characterization in flow cytometry
Publication Date: 2026.03.25 BECKMAN COULTER INC
  • EP4533066B1 patent drawingFigure 1
  • EP4533066B1 patent drawingFigure 2
  • EP4533066B1 patent drawingFigure 3

AI summary

A method of characterizing particles in flow cytometry includes determining a first pulse width value of a particle using a first technique. The method includes determining a second pulse width value of the particle using a second technique. The method further includes comparing the first and second pulse width values, and characterizing the particle as a concatenated particle when a difference between the first and second pulse width values exceeds a threshold.