PRM-Based Targeted Proteomics Quantification Service
Proteins are the executors of life's activities, and their expression levels under different physiological and pathological conditions directly determine cellular function and disease development. However, obtaining accurate and reliable quantitative information about proteins has always been a key challenge in life science research. Among the various protein quantification methods, Parallel Reaction Monitoring (PRM) technology has become the mainstream approach in targeted proteomics because of its high specificity, high sensitivity, and high-throughput capabilities.
How It Works
Figure 1. PRM workflow. (Source: Rauniyar N. 2015)
PRM is an ion monitoring technique based on high-resolution, high-precision mass spectrometry. Compared to traditional single/multiple reaction monitoring (SRM/MRM) technology, PRM offers stronger quantification capability and broader applicability. PRM utilizes a quadrupole coupled with high-resolution mass spectrometry, and achieves precise quantification of target proteins or peptides through the following steps:
- Primary Mass Analysis: The quadrupole (Q1) selectively detects the parent ion of the target peptide, ensuring that only ions with specific mass-to-charge ratios enter the collision cell.
- Collision-Induced Dissociation: Under collision energy, the parent ion undergoes directed fragmentation in the collision cell, producing multiple fragment ions.
- High-Resolution Detection: The high-resolution mass analyzer precisely detects all fragment ions and acquires complete secondary mass spectrum information.
- Quantification Analysis: By extracting fragment ion intensity information and applying internal standard correction, relative or absolute quantification of the target peptide is achieved.
This multi-level selection and detection mechanism enables PRM to accurately identify and quantify target proteins in complex biological samples, reliably distinguishing even between highly similar protein subtypes or post-translationally modified peptides.
Our Services
Our company's PRM-based targeted proteomics service covers the following core application areas:
1. Verification of Proteomics Discovery Results
Perform targeted and precise verification of differentially expressed proteins discovered in previous proteomics studies (such as Label-free, TMT, or DIA discovery analyses), increasing the credibility of research conclusions.
2. Quantification of Post-Translationally Modified Proteins
Selective detection and quantification of various post-translational modification sites such as phosphorylation, acetylation, and ubiquitination, revealing the molecular mechanisms of protein function regulation.
3. Screening and Validation of Biomarkers
In disease-related research, perform absolute quantification of candidate biomarkers to support the development and validation of clinical diagnostic assays.
4. Absolute Protein Quantification
Through synthetically labeled stable isotope-tagged peptides, achieve absolute quantification of target proteins, applicable to studies of drug metabolism and protein-protein interactions.
5. Differentiation of Homologous Proteins and Variants
Utilize PRM to precisely distinguish and quantify proteins with highly similar sequences, supporting research on protein subtypes and genetic mutations.
Workflow
The standard analytical workflow for PRM-based targeted proteomics quantification consists of six key steps:
Based on research objectives and prior data or literature, identify proteins of interest. Use professional databases to select the most suitable unique peptides for detection, considering factors such as enzymatic digestion efficiency, modification sites, and physicochemical properties.
For absolute quantification needs, synthesize stable isotope-labeled peptides as internal standards to correct signal fluctuations and improve batch-to-batch data consistency.
Perform sample lysis, protein quantification with standardized sample loading, trypsin digestion, and desalting purification to ensure high-quality, reproducible peptide mixtures.
Conduct detailed optimization of mass spectrometry parameters for each peptide, including collision voltage, retention time windows, and parent-to-fragment ion pair selection, establishing stable and reproducible detection methods.
Perform precise sample analysis using QC samples and pooled samples for cross-validation, implementing rigorous quality control monitoring (such as coefficient of variation and internal standard stability).
Use professional analysis software for peak identification, integration, and quantification calculations. Combine statistical analysis and significance assessment to provide visualization-based reports and biological interpretation.
Sample Submission Guidelines
| Sample Type | Requirements |
| Plant leaves | Wet weight ≥ 0.2 g |
| Plant roots, stems, wood, and bark | Wet weight ≥ 5 g |
| Cell samples | Cell count ≥ 1×10^7 |
| Tissue samples (human, animal, microbial) | Wet weight ≥ 50 mg |
| Serum, plasma | Volume ≥ 100 μL |
| Cerebrospinal fluid | Volume ≥ 200 μL |
Leveraging its high specificity, high sensitivity, and absolute quantification capability, PRM-based targeted proteomics technology provides robust technical support across multiple domains including protein function research, post-translational modification analysis, and clinical biomarker validation. Whether in fundamental research or translational applications, whether handling diverse sample types or comprehensive modification types, our PRM service can be flexibly customized to meet your specific needs, helping your research projects achieve breakthrough advances in proteomics exploration.
Reference
- Rauniyar N. Parallel Reaction Monitoring: A Targeted Experiment Performed Using High Resolution and High Mass Accuracy Mass Spectrometry. Int J Mol Sci. 2015 Dec 2;16(12):28566-81.
