SRM Targeted Proteomics Detection Technology

SRM (Selected Reaction Monitoring) is a mass spectrometry technology mainly used for quantitative analysis of target proteins or peptides. SRM usually operates on a triple quadrupole mass spectrometer and is a highly sensitive and specific technique.

 

Some Basic Principles and Steps of SRM Targeted Proteomics

1. Target Selection

Before the experiment begins, the target proteins or peptides to be measured need to be chosen first.

 

2. Peptide Selection

To detect proteins, representative peptides (often referred to as "peptidome" or "signature peptides") are typically selected for quantification.

 

3. Conversion to Preset Ions

Samples are ionized in the mass spectrometer, and preset precursor ions are selected in the first quadrupole.

 

4. Fragmentation

The selected precursor ions collide with inert gas in the collision cell to produce fragment ions.

 

5. Detection of Specific Fragment Ions

In the second quadrupole, specific fragment ions are selected and detected. This step provides the high specificity of SRM.

 

6. Quantification

By measuring the intensity of specific ions of specific peptides, the abundance of target proteins in the sample can be quantified.

 

Due to the high specificity and sensitivity of SRM, it has become an important tool in clinical research and biomarker validation. Compared with traditional non-targeted mass spectrometry proteomics technologies, SRM provides higher quantitative accuracy, especially in the case of low abundance proteins.