MS2 Reporter-Ion Quantitation With Interference Signal Decomposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multiplexed isobaric labeling techniques in mass spectrometry suffer from ratio distortion due to co-fragmentation of interfering ions, leading to inaccurate quantitation of analytes, particularly in MS2 analysis.
Innovation Solution
A computational method to decompose mass spectrometric signals into components correlated and uncorrelated with the peptide of interest, using non-negative least squares analysis to correct reporter-ion ratios, allowing for accurate quantitation without the need for MS3 analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MS2 analysis is used for multiplexed isobaric labeling quantitation, then sample throughput is increased, but ratio distortion occurs due to co-fragmentation of interfering ions leading to inaccurate quantitation
Solution Approach 1:
The patent segments the mass spectrometric signal into multiple components using non-negative least squares analysis. The reporter ion signal is decomposed into contributions from the peptide of interest and interfering ions, allowing accurate quantitation by isolating the relevant signal component while maintaining high throughput MS2 analysis.
2Measurement precision
If MS3 analysis is used to eliminate ratio distortion, then quantitation accuracy is improved, but sample throughput decreases due to additional analysis time
Solution Approach 1:
The patent extracts the interfering ion contributions from the total reporter ion signal using computational decomposition. By taking out the unwanted signal components mathematically, the method achieves MS3-level accuracy without requiring the additional physical separation step, thus maintaining high throughput.
3Measurement precision
If computational decomposition is applied to correct reporter-ion ratios, then ratio distortion is reduced, but data processing complexity increases
Solution Approach 1:
The patent replaces complex physical separation methods (like MS3) with computational mathematics (non-negative least squares analysis). This substitution of mechanical/physical processes with algorithmic processing achieves the same goal of eliminating ratio distortion while simplifying the overall experimental workflow.
Data Source
Figure 1A~1C
Figure 2
Figure 3
AI summary
A method for correcting abundance ratios between pairs of isobaric reporter ions comprises: (a) measuring, for each liberated reporter-ion moiety the variation, with time, of a signal from said moiety; (b) identifying a first set and a second set of reporter-ion moieties for which the respective signal is, respectively, positively correlated with and not correlated with, the time variation of one or more other signals or variables that pertain to the detection of one or more peptides of interest; (c) for each reporter-ion moiety, decomposing the respective measured mass spectrometric signal into first and second portions that, respectively are and are not attributable to the peptide; (d) for each identified reporter-ion moiety, setting a respective adjusted mass spectrometric signal as being the respective portion of the signal that is attributable to the peptide; and (e) calculating corrected reporter-ion ratios based on the adjusted mass spectrometric signals.