Parallel Reaction Monitoring (PRM) Service
MtoZ Biolabs provides Parallel Reaction Monitoring (PRM) services for targeted quantitative analysis of predefined peptides and selected protein targets, supporting focused validation with high-resolution LC-MS/MS and fragment-ion based quantitative evaluation.
This service is suitable for projects with established candidate proteins, peptides, or predefined PTM targets, including follow-up validation after discovery proteomics and targeted comparison of selected analytes across experimental groups.
- Targeted quantification of predefined peptides and proteins
- High-resolution PRM with multi-fragment ion evaluation
- Suitable for follow-up validation after proteomics discovery
- Supports predefined PTM targets with tailored workflows
Parallel Reaction Monitoring (PRM) is a targeted mass spectrometry technique used to quantify predefined peptides and evaluate the abundance of proteins represented by selected proteotypic peptides. Unlike discovery proteomics, which broadly profiles proteins across a sample, PRM focuses MS acquisition on selected targets and is particularly suitable when candidate proteins or peptides have already been identified.
MtoZ Biolabs offers PRM targeted proteomics services covering target peptide selection, PRM method development, LC-MS/MS analysis, and quantitative data analysis. The service can support validation of differential proteins identified by discovery proteomics, quantitative comparison of selected targets across experimental groups, and targeted analysis of predefined modified peptides.
During PRM analysis, selected precursor ions are isolated and fragmented, and high-resolution MS/MS spectra containing multiple fragment ions are recorded. Suitable fragment-ion chromatographic signals are subsequently used for target confirmation and quantitative evaluation.
Analysis Workflow
1. PRM Method Development
Representative peptides are selected for the target proteins based on factors such as sequence uniqueness, digestion behavior, MS detectability, and potential analytical interference.
When previous proteomics data are available, experimentally detected peptides can provide useful evidence for target selection. For projects requiring absolute peptide quantification, appropriate stable isotope-labeled peptide standards can be incorporated according to the analytical design.
2. LC-MS/MS Analysis
Proteins are typically enzymatically digested into peptides and separated by liquid chromatography.
Predefined precursor ions are selectively isolated and fragmented during PRM acquisition. High-resolution MS/MS spectra are collected for each target precursor, allowing multiple characteristic fragment ions to be monitored.
3. Quantitative Data Analysis
Fragment-ion chromatograms are extracted and integrated using targeted proteomics data analysis workflows.
Quantitative evaluation considers fragment-ion consistency, retention behavior, peak shape, signal intensity, and potential interference. When isotope-labeled internal standards are used, light-to-heavy signal ratios can also support quantitative analysis.
Figure 1. Workflow for PRM
Service Advantages
1. High Selectivity for Defined Targets
PRM selectively monitors predefined precursor ions and evaluates multiple high-resolution fragment ions from each target peptide. This provides multiple signals for confirming the identity of the target in complex sample backgrounds.
2. Focused Targeted Acquisition
Instead of distributing acquisition across a broad proteome, PRM focuses analytical capacity on a defined target list. This makes it suitable for follow-up studies in which the proteins or peptides of interest have already been identified.
3. Flexible Fragment-Ion Evaluation
PRM records multiple product ions from each selected precursor. During data analysis, fragment ions affected by interference can be excluded while more suitable signals are retained for quantitative evaluation.
Sample Submission Requirements
For more sample details, please consult our technical team.
Applications
1. Validation of Differential Proteins
PRM can be used for follow-up validation of candidate differential proteins identified by label-free, DIA, TMT, iTRAQ, or other quantitative proteomics approaches.
Representative peptides are selected for the candidate proteins and developed into PRM targets for quantitative comparison across experimental samples.
2. Candidate Biomarker Verification
Candidate proteins identified during discovery studies can be further evaluated using PRM in research samples.
Targeted measurement of representative peptides can help determine whether abundance differences observed during the discovery stage are reproducible in additional samples.
3. Targeted PTM Quantification
PRM can be applied to predefined modified peptides or modification sites when suitable targets have been established.
Depending on the modification type and target abundance, PTM-specific enrichment and dedicated method development may be required before PRM analysis.
4. Signaling Pathway and Target Protein Research
PRM can monitor abundance changes or predefined PTM changes in selected proteins associated with signaling pathways or other defined biological processes.
This approach is useful when the research question has already been narrowed to a specific set of proteins that require targeted quantitative comparison.
Contact Us
MtoZ Biolabs provides PRM analysis for researchers who need targeted quantitative validation of selected proteins, peptides, or predefined PTM targets.
To discuss project feasibility, please provide your target proteins or peptides, sample type, and quantitative objective. Our technical team can help evaluate an appropriate PRM analysis strategy.
