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MALDI-MS Determination of molecular weight; has been replaced by HPLC-ESI-MS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.