How Much Protein Is Needed for Mass Spectrometry Sequencing?

The amount of protein needed for mass spectrometry determination of protein sequence depends on several factors, including the sensitivity of the mass spectrometer, the purity of the sample, the type of analysis (such as peptide mapping, protein identification or post-translational modification analysis) and the properties of the specific protein. With advances in technology, the sensitivity of mass spectrometry is increasing and the amount of sample required is decreasing. It is generally in the following range:

 

1. Traditional Mass Spectrometry Analysis

For older or more common mass spectrometry equipment, it typically requires several micrograms to tens of micrograms of protein to analyze a protein sample.

 

2. High Sensitivity Mass Spectrometers

For modern high sensitivity mass spectrometers, such as those using electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) technology, only a few hundred nanograms to a few micrograms of protein are usually needed for effective analysis.

 

3. Single Cell Proteomics

In some high-end applications, such as single-cell proteomics research, mass spectrometry analysis can be performed with very small amounts of sample (even approaching the protein level of a single cell). Such analyses typically require special sample handling and highly sensitive mass spectrometry techniques.

 

The preparation and handling of the sample is crucial for obtaining high-quality mass spectroscopy data. Protein purification, digestion, desalting, and other pre-treatment steps can significantly affect the quality of the analysis results.