Overview

Introduction to Label-free Proteomics

Label-free proteomics is a method used to analyze and quantify proteins in biological samples without the use of stable isotope labels. This approach relies on comparing the mass spectrometry (MS) data from different samples directly, rather than incorporating chemical labels or tags into the proteins.

The core principle of label-free proteomics involves the direct measurement of peptide signals from mass spectrometry data. There are two main strategies used in label-free quantification:

1. Peak Intensity Measurement: This strategy calculates and compares the intensity of chromatographic peaks corresponding to peptides. The peak area of each peptide is measured and used to infer the quantity of the corresponding protein.
2. Spectral Counting: This method counts the number of tandem mass spectrometry (MS/MS) spectra that identify peptides from a given protein. The number of spectra correlates with the abundance of the protein in the sample.

Services

Label-free Proteomics Service for Exosomes

In proteomic analysis of exosome samples, label-free techniques are the most commonly used. This is because exosome samples often come from various sources, such as different cell lines or fluids, leading to relatively large differences in the protein spectrum. Therefore, besides quantitative differences in common proteins, differential protein analysis with and without the label is also involved. In such cases, label-free methods are recommended.

Firstly, in a label-free experiment, there is no limit to the number of samples, as each sample is analyzed separately. For large-scale analysis involving many samples, label-free proteomics is preferred due to its flexible research design and convenience for multi-group comparison. Additionally, because of multiplexing, samples are not diluted, allowing for the detection of specific low-abundance proteins under particular conditions. When bias is avoided in research design and reference samples are added to monitor the performance of the entire experiment, label-free proteomics provides a favorable strategy for biomarker discovery.

Features

• No need for expensive isotope labeling reagents.
• Suitable for comparing differential proteins among different species.
• Overcomes the limitations of labeling and quantitative technologies regarding the number of samples, offering flexibility and convenience.

If you would like to conduct Label-Free Proteomics analysis on your exosome samples, please contact us for a quote.

FAQs

• Phosphorylated Exosomal Proteomic Detection
• Labeled Exosomal Proteomic Detection
• Four-Dimensional Exosomal Proteomic Detection
• MRM/PRM Targeted Exosomal Proteomic Quantitative
• Ultra-sensitive Targeted Exosomal Proteomic Detection
• Glycosylated Exosome Detection
• Exosomal Peptidomic Detection