Label-Free

Label-Free quantitative proteomics (LFQ) is a method that determines the relative abundance of proteins directly using Mass Spectrometry (MS) without introducing stable isotope labels into the sample. The core principle of LFQ relies on the linear correlation between the signal intensity detected by MS and the protein concentration. LFQ quantification is primarily performed using two methods:(1) Peak Area Integration: Determines the relative abundance of each protein or peptide by calculating the peak area of characteristic ions during MS analysis. (2) Spectral Counting: Estimates the protein's relative abundance in the sample by counting the number of mass spectra identified for the target protein.LFQ is suitable for nearly all types of proteins or peptides, particularly those with significant abundance variations in biological samples. It is particularly advantageous for experiments with straightforward sample preparation, limited sample quantities, or where isotope labeling is not feasible.

 

MtoZ Biolabs offers Label-Free analysis services to assist researchers in advancing biomedical research, drug development, and functional studies. Please contact us for more information about our services.

 

Analysis Workflow

1. Sample Preparation: Extract proteins and perform enzymatic digestion (typically with trypsin).

 

2. Liquid Chromatography Separation: Separate the digested peptides using liquid chromatography (e.g., reverse-phase high-performance liquid chromatography, RP-HPLC).

 

3. Mass Spectrometry Detection: Detect peptides using a mass spectrometer (e.g., Q-TOF, Orbitrap).

 

4. Data Processing: Analyze the MS data using software (e.g., MaxQuant, Proteome Discoverer) to determine the relative abundance of proteins across samples.

 



Zhu, W. et al. J Biomed Biotechnol. 2010.

Figure 1. General Approaches of Label-free Quantitative Proteomics

 

Applications

1. Disease Research: Identify protein biomarkers associated with diseases and investigate disease mechanisms.

 

2. Drug Development: Assess the impact of drugs on protein expression and identify drug targets.

 

3. Biomarker Discovery: Discover potential biomarkers by comparing protein expression levels under different conditions.

 

4. Functional Studies: Explore the roles and regulatory mechanisms of proteins in various biological processes.

 

Sample Submission Requirements

 



 

Note: Solid samples can be transported with ice packs; liquid samples can be vacuum-dried or freeze-dried and transported with ice packs or transported with dry ice. Welcome to call for consultation.

 

Service Advantages

1. No Need for Labeling: Eliminates additional steps and potential errors associated with sample labeling.

 

2. Wide Applicability: Suitable for various types of proteins or peptides without special treatment.

 

3. High Throughput: Capable of analyzing numerous samples simultaneously, making it ideal for large-scale studies.

 

4. Accurate Relative Quantification: Provides high accuracy and reliability in relative quantification based on MS signal intensity.