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School of Biological and Chemical Sciences

Mass Spectrometry Lab - Services

Services

Exact molecular mass of small molecules

Exact mass of newly synthesised chemical products with a mass error less than 3 ppm. Supply 0.1 to 1 mg of compound, dry or in solution. Compatible solvents are methanol and acetonitrile.

Structural characterization of small molecules

The HRMS Synapt G2Si provides a complete characterization of small molecules. Supply 0.1 to 1 mg of compound, dry or in solution. Compatible solvents are methanol and acetonitrile.

Peptide MW, purity and sequencing analysis by HRMS

We can estimate peptides purity, molecular weight, and confirm their sequence by MS fragmentation. 50 mL of 0.1 mg/ml will be sufficient for mass spec analysis. We will dilute as appropriate prior to the analysis. Suitable solvents to use are water and methanol. Provide sequence of the peptide in the submission form.

Protein intact mass analysis by MALDI-TOF or ESI-qTOF

P1

The average Molecular weight of a protein can be obtained by MALDI-TOF analysis, or by deconvolution of mass spectra following ESI-qTOF analysis. Please supply 0.5 mg of protein if greater than 10 kDa. Suitable solvents to use are water, Ammonium acetate and methanol. Provide sequence of the protein in the SBCS mass spectrometry service request form.  

Native MS analysis of protein oligomers

The SBCS mass spectrometry laboratory offers analysis of noncovalent protein–protein and protein–ligand complexes. Supply 20 mL of 1 mM concentration of the complexed proteins, and we will dilute as appropriate for the analysis.

Protein identification

P2

Proteins can be identified by LC-MSe from solution, gel, or from a pull-down assay. Proteins are in-gel or in–solution digested with an endopeptidase, usually trypsin, and the resulting peptides are separated by liquid chromatography in line with a mass spec to determine their mass, and to confirm their sequence by MSe. The masses and /or sequences of the proteolytic peptides are submitted to a database library for identification.

To prepare samples:

Gel: The protein/s of interest should be clearly visible on a Coumassie blue dye R250-stained SDS-PAGE gel. The gel should be de-stained and washed thoroughly. If stored, leave it in 25% acetic acid or in 0.02 % sodium azide and keep it refrigerated. Place the gel on a clean surface and excise the band of interest.   Cut as close as possible around the stained protein. Place the protein ‘slice’ in an Eppendorf tube and keep it refrigerated. Submit the sample along with a picture of the gel. 

For pull-down experiments:

For pull down experiment, we require 10-15 µg of protein for endopeptidase digestion. The protein can be in solution or still attached to the beads. Submit the sample, fill out a sample submission form noting as many details as possible (protein expected, MW, antibody used).

Lipid profile analysis

Lipid profile analysis and identification will be provided from any biological source. Contact us below to discuss sample preparation and type of analysis to perform.

Contact the mass spectrometry laboratory

Quantitative analysis of small and large molecules in complex matrices

A quantitative method by LC-MSMS can be developed by the SBCS Mass Spectrometry Laboratory.   The procedure entails fragmentation of the small molecule analyte and selection of an ion to quantitate.   A labelled internal standard will be needed for the analysis, and we will help with the selection of a suitable reference molecule.

Quantitative analysis of proteins requires endopeptidase digestion and selection of a proteolytic peptide to be quantified.   A suitable labelled peptide is necessary as a reference molecule. The mass spectrometry laboratory will help with the selection of a labelled peptide.    

The laboratory also offers label-free, relative and absolute quantification of proteins. Contact us below to discuss workflow of the analysis.

Contact the mass spectrometry laboratory

Full peptide mapping (Protein sequencing, PTM identification and quantification, disulphide bride analysis)

P3

Full peptide mapping of proteins is an available service provided by the SBCS mass spectrometry laboratory.   Peptide mapping entails endopeptidase digestion of the protein of interest, peptide sequence, analysis of post translational modifications (PTM), relative quantitation of PTMs and analysis of disulphide bridges.  

Supply about 0.5- 1 mg of protein for the analysis.

Glycan analysis by MS

Contact the mass spectrometry laboratory

Consultation on sample preparation for analytical experiments

Contact the mass spectrometry laboratory