Phenomena          Procedures
Aggregation SDS-PAGE, SEC-HPLC. light scattering 
Deamidation, Oxidation Peptide map, HPLC, IEF, MS 
Proteolytic Cleavage Peptide map, SDS-PAGE, HPLC, IEF, MS 
Amino Acid Substitutions AAA, Peptide map, MS, protein sequence, CE 
Translation Mutations Peptide map, HPLC, IEF, MS, CE 
Host Cell Proteins SDS-PAGE, Western blot, ELISA 
Media Components SDS-PAGE, Western blot, HPLC, ELISA 
Nucleic Acids DNA hybridization, UV, Protein binding 
Affinity Antibodies SDS-PAGE, Western blot, ELISA 
Proteases/Nucleases HPLC, Western blot, ELISA 
Leachates/Extractables HPLC, MS, GC, gravimetric analysis 
Process Residuals Karl Fisher moisture, GC, ion chromatography 
Table 4: Analytical methods for biotechnology product impurities.