Protein Characterization Services (Catalog No: SC1576):

Identification of proteins by their immunologic reaction with antibodies of known specificity.

Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) mass spectrometer is often used in peptide mass fingerprinting; and MALDI TOF/TOF is often used to reveal amino acid sequence of peptides.

Peptide mapping involves cleavage of proteins with an enzyme having high specificity (usually trypsin), whereupon the resulting proteolytic products are subjected to analysis by mass spectromety. Through the use of an appropriate computer algorithm, the masses determined for the proteolytic peptides are compared with masses calculated for theoretically possible enzymatic cleavage products for every sequence in a protein/DNA sequence database. The protein is identified based on an evaluation of this comparison. Peptide mapping plays an important role in the ensemble of analytical tools that are used for lot release testing of recombinant therapeutic proteins. Peptide maps are primarily used to establish product identity by confirming the primary structure (the amino acid sequence) of a product on a lot-to-lot basis.

Amino acid sequence, N and C terminal sequence can provide information of protein structure, confirmation of protein intactness. This is normally done with enzyme digestion, peptide mapping and combination with molecular weight analysis.

Disulfide bridge analysis is used to analyze co-translational and post-translational modifications of proteins by assigning disulfide bridge and Cystine linkage sites are identified.

Carbohydrate chains in glycoprotein pharmaceuticals play important roles for the biological activities, and the structure and compositions of carbohydrate chains are dependent on the conditions for their production. Therefore, evaluation of the carbohydrate chains is quite important for productive process development, characterization of product for approval application, and routine quality control.

Capillary electrophoresis is an analytical technique that separates ions based on their electrophoretic mobility with the use of an applied voltage. It has very high resolution and gives results in very short time. CE has been a powerful tool to analyze the isoforms of protein caused by different post-translational modifications.

Amino acid analysis can be used to quantify protein and peptides, to determine the identity of proteins or peptides based on their amino acid composition, to support protein and peptide structure analysis, to evaluate fragmentation strategies for peptide mapping, and to detect atypical amino acids that might be present in a protein or peptide.

Isoelectric Focusing (IEF), also known as electrofocusing, is a type of zone electrophoresis for separating different molecules by their electric charge differences.

HPLC is used to determine the identity, content and purity of proteins. SEC-HPLC can be used to determine degree of aggregation.

Antibody-Dependent Cell-mediated Cytotoxicity (ADCC) and Complement-Dependent Cytotoxicity (CDC) are major antibody-based mechanisms of immune defense system. The ADCC and CDC activities are always the most important criteria to evaluate the antibody efficacy on the drug targets. ( Bioassay ADCC&CDC Services )

Biacore analysis can characterize molecule – molecule interaction such as affinity and kinetics analysis.( Biomolecular Interaction Analysis Services )

Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) is a technique to separate proteins according to their electrophoretic mobility differences caused by the length of polypeptide chain or molecular weight.

Endotoxins are structural molecules of the bacteria recognizable by animal immune systems, which are frequent contaminants in proteins expressed from bacteria. Endotoxins must be removed prior to in vivo applications.

Host Cell Protein and DNA are process related impurities from the expression organism. It is an essential part of manufacturing Biopharmaceuticals that is to monitor and quantitate the levels of Host Cell Protein (components of the host cell system) contamination in the final drug product to ensure product quality. The amount of residual protein and DNA in a drug's final dosage form must meet regulatory guidelines.

Protein A is a bacteria protein binding many mammalian proteins (most notably immunoglobulins, IgGs), which can disrupt host immune systems. The amount of residual protein A in a drug's final dosage form must meet regulatory guidelines.

Enzyme-Linked Immunosorbent Assay (ELISA) is used for detection and quatitation of proteins, also it can be used to determine impurities such as trace amount of HCP, residual protein A etc.

Bicinchoninic acid (BCA), Bradford, and Lowry assays are multiple methods used to detect protein concentrations.

Circular Dichroism (CD) relies on the differential absorption of left and right circularly polarised radiation by chromophores, which either possess intrinsic chirality or are placed in chiral environments. CD has been used extensively to give useful information about protein structure, the extent and rate of structural changes, ligand binding, to assess the structure and stability of the designed protein fragments.