iTRAQ Quantitative Proteomics

iTRAQ (Isobaric Tags for Relative and Absolute Quantitation) is an isotope tagging technology for relative and absolute quantitation, extensively used in proteomics research. iTRAQ technology marks proteins or peptides to achieve protein quantification analysis, thereby revealing the dynamic changes of proteins in biological processes.

 

The core of iTRAQ technology is to use isotope labeling reagents to label protein samples. These labeling reagents consist of two parts: the balance region and the reporter region. The balance region ensures that the labeled peptides have the same mass, while the reporter region generates different fragment ions during mass spectrometry for quantitative analysis.

 

Analysis Workflow

The operational process of iTRAQ technology mainly includes sample processing, enzyme digestion, labeling, mixing, separation, and mass spectrometry. Among them, sample processing is the basis of the experiment, including protein extraction, purification, and concentration, etc.; Enzyme digestion cuts the protein into peptides, providing convenience for subsequent labeling; Labeling combines iTRAQ reagents with peptides to form labeled peptides; Mixing involves mixing labeled peptides from different samples for mass spectrometry analysis; Separation uses liquid chromatography to separate mixed peptides to improve the accuracy of mass spectrometry analysis; Mass spectrometry analyzes peptides through a mass spectrometer to obtain protein quantification information.

 

The Advantages and Limitations of iTRAQ Technology

iTRAQ technology has the advantages of simultaneous analysis of multiple samples, high throughput, high sensitivity, and high accuracy, making it an important tool in proteomics research. However, iTRAQ technology also has some limitations, such as the uncertainty of labeling efficiency, labeling preference, and the complexity of data processing.