ESI-MS Intact Protein Analysis

Electrospray ionization mass spectrometry is a special soft ionization technology that can generate gas phase ions with multiple charges more gently, reducing the mass-to-charge ratio range of the molecules to be measured. The product ions of multi-charged precursor ions can also provide more structural information than the product ions of single-charged precursor ions. Electrospray ionization mass spectrometry not only can obtain accurate molecular weight of compounds, but also can be used for quantitative and qualitative analysis of trace or trace biologically active molecules. It is also suitable for studying weak bond interactions. Combined with collision-induced dissociation technology, electrospray ionization mass spectrometry can also be used for structural analysis, reaction mechanism, and non-covalent bonding capabilities.

From early research and development, characterization analysis, process optimization to CMC and QC analysis, biopharmaceuticals have complexity and uncertainty in every link. Creative Proteomics provides high resolution mass spectrometry biopharmaceutical solutions to support your product from development to production.

ESI-MS Intact Protein Analysis Schematic diagram of the main process of ionization

We Provide but Not Limited to:

  • Molecular weight determination.
  • Peptide map analysis.
  • Analysis of Biopharmaceutical Host Cell Residual Proteins (HCPs).
  • Study the folding path of proteins: analyze the conformational changes of protein molecular ions, obtain the transition state information of conformational changes, and understand the process of spatial conformation.
  • Study the non-covalent effect of peptides and metals.
  • Study the non-covalent effect of protein and protein, peptide and peptide, protein and DNA, protein and peptide: intramolecular binding force or non-covalent binding selectivity, affinity, stability, determination of binding site, calculation of binding constant or dissociation constant.

Advantages of ESI-MS Intact Protein Analysis Service:

  • High sensitivity, high accuracy, easy to operate and fast detection.
  • ESI-MS can be effectively used in combination with chromatography, and is suitable for the identification or structure determination of trace substances in complex systems.
  • Suitable for the analysis of strong polarity, difficult volatilization or thermal instability compounds.
  • The limited detection conditions are few and the signal is easy to be analyzed.
  • The information of transition state can be obtained, and the composition and conformation of polypeptide and protein molecules can be studied effectively.

Sample Requirements

  • Purity>90%.
  • Avoid detergents and keep buffer concentration at a minimum.
  • Quantity>40ug.
  • Acceptable buffers: ammonium acetate, ammonium bicarbonate, ammonium formate.
  • Avoiding buffer: HEPES, PBS, MES, MOPS, and Tris.
  • Avoiding detergents: SDS, PEG, PPG, Tween, CHAPS, Triton, and urea.
  • Avoiding salts: Alkylammonium salts, guanidinium salt, metal cations and inorganic anions such as phosphate, sulfate, and halides.

Creative Proteomics' analytical scientists can provide customers with ESI-MS intact protein analysis service. We will deliver raw data, concise and clear results report, detailed bioinformatics analysis reports.


  • Loo J A. Electrospray ionization mass spectrometry: a technology for studying noncovalent macromolecular complexes. International Journal of Mass Spectrometry, 2000, 200(1-3): 175-186.

*For Research Use Only. Not for use in the treatment or diagnosis of disease.

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