Proteome Factory offers a comprehensive array of analytical service portfolio for quality control of peptides, recombinant proteins, protein drugs and monoclonal antibodies.
For protein mass determination we have replaced MALDI-MS with HPLC-ESI-MS using ion trap or FTICR mass spectrometry, followed by charge state deconvolution. Its advantage is a higher resolution which can resolve e. g. main glycoisoforms of mABs easily. Samples need to be of higher quality, e. g. purified proteins are required. Salts are no problem; please contact us if detergents are present in the formulation. We have successfully analysed intact antibody constructs of up to 220 kDa by HPLC-ESI-MS.
Protein mass determination
Method | Aim of analysis |
nanoESI-MS | Determination of molecular weight (of pure, salt-free proteins/peptides) |
HPLC-ESI-MS of intact protein | Determination of molecular weight by HPLC and ion trap mass spectrometry, widely applicable |
HPLC-ESI-FTICRMS | Determination of molecular weight by HPLC and high resolution mass spectrometry, for precise masses |
MALDI-MS | Determination of molecular weight; has been replaced by HPLC-ESI-MS |
SDS-PAGE | Protein mass determination by gel electrophoresis and comparison to standard proteins |
Protein sequence analysis
Method | Aim of analysis |
N-terminal sequencing | Analysis of the N-terminal amino acid sequence and homogenity of the N-terminus |
Protein sequencing | Analysis and validation of the primary amino acids sequence of complete proteins by mass spectrometry as well as N-terminal and internal Edman protein sequencing |
Peptide mapping and protein identification | Confirmation of protein identity and detectable peptides by nanoHPLC-ESI-MS/MS after tryptic (or other suitable proteolytic) protein digest |
Analysis of disulfide bridges | Confirmation and determination of the position of disulfide bridges |
Analysis of post-translational modifications | Detection and conformation of sequence position of post-translational modification |
Determination of purity and impurities
Method | Aim of analysis |
2D electrophoresis, isoelectric focussing, SDS-PAGE, western blot, MeCAT | Determination of homogenity and purity of a product or batch; detection and quantfication of isoforms and protein species |
2D electrophoresis and protein identification | Determination of homogenity and purity of a product or batch as well as identification of proteins, protein contaiminations and degradation products |
Chromatography | Determination of homogenity and purity of protein and peptide products or batches. A multitude of separation techniques is applicable (Reversed Phase, Size Exclusion, Ion Exchange etc) |
Bradford assay for protein concentration determination | Determination of total protein concentration in a product or batch |
MeCAT protein quantification by MeCAT labeling and ICP-MS | Absolute ultra sensitive and exact protein quantification in a product or batch |
Please contact us if you need specific other protein analytical methods, advanced protein analysis, the development of new methods and techniques to fulfil your requirements. (de)