Proteome Factory offers the following standard analytical service portfolio for quality control of peptides, recombinant proteins, protein drugs and monoclonal antibodies. 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.

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.

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MALDI-MS	Determination of molecular weight; has been replaced by HPLC-ESI-MS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
Protein identification and peptide mapping	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