An antibody's sequence can be determined from the protein when the original hybridoma cells are lost. 

This is done by multiple enzymatic digests and, if required, chemical derivatisation for subsequent analysis of the resulting peptides high resolution mass spectrometry (LCMS/MS) and exhaustive data analysis. Initial database searches using Proteome Factory's in house curated antibody databases give a starting point for de novo sequencing of CDR regions. The results are indirectly confirmed against the intact masses of the deglycosylated heavy chain (HC) and light chain (LC).  

Only the isobaric amino acids Leucine and Isoleucine cannot be discriminated by mass spectrometry alone. When information from germline sequences does not give sufficient confidence, we can perform internal Edman sequencing of such regions for highest confidence. 

To ensure both confidentiality and data consistency/integrity, Proteome Factory performs all required steps from sample preparation to data analysis in our own labs in Berlin, Germany. 

Please contact our specialists to discuss how we can advance your project.