How to characterize antibody glycosylation by HILIC-MS
Question: What is N-glycosylation and how do I characterize the N-glycosylation of my antibody? Is it possible to compare batch-to-batch variations? Answer: Glycosylation is...
Simple way to perform label-free quantification of Host Cell Proteins
Question: I find it difficult to get an accurate label-free quantification of Host Cell Proteins with LC-MS. It also seems that...
Quickly compare HCP in different process steps, without an ELISA
Question: I have spent days trying to set up a useful ELISA assay for detecting Host Cell Proteins (HCPs) in my process samples. I'm...
How to identify peaks observed by UV-HPLC in stability studies
Question: We have developed a Reversed-Phase (RP) UV- HPLC chromatography method. It is used for stability studies of our new pharmaceutical protein. How do we...
What is SWATH and why is it an advantage for Host Cell Protein analysis?
Host Cell Proteins (HCPs) in protein biopharmaceuticals can be analyzed by mass spectrometry - for both identification and quantification of...
4 reasons why N-terminal sequencing should be done by Edman degradation
Question: How do I obtain the N-terminal sequences of the heavy chain and light chain of my monoclonal antibody? Answer: mAb N-terminal sequence...
Verifying Ile/Leu residues in de-novo sequencing of antibody
Question: I was told that de-novo sequencing by mass spectrometry is not able to distinguish between Ile and Leu residues in my...
What purity is required for de-novo sequencing of my antibody?
Question: My monoclonal antibody is not 100% pure, what is the purity required for de-novo sequencing? Answer: We typically observe two types of protein impurities in...
Antibody de-novo Sequencing: How to get 100% sequence coverage
Question: Is it possible to perform a de-novo sequencing of my purified monoclonal antibody without the hybridoma cells? Answer: Yes! – Your purified antibody can...
Why disulfide bridges are critical quality attributes of biologics
Question: The activity of my biopharmaceutical protein is low, and I suspect that it is related to decreased protein stability. What...
Why you need accurate concentration determination of protein standards
How do I quantify my protein standard? Have you ever questioned the quantitative data you get from Bradford, Lowry or BCA protein quantification...
Find the Molar Extinction Coefficient of your protein in 3 small steps
Question: I have a purified protein that I would like to quantify accurately in my lab using 280 nm UV measurement...
Identification of small host cell proteins (low Mw HCPs)
Question: Could you suggest an analysis method to detect low Mw HCPs (small HCPs) below 20 kDa? I work on a drug...
3 steps to identify & quantify HCP in drug substance homolog to host cell
Question: My HCP antibodies show a reaction towards a drug substance band in my Western blot. Is it possible that it is...
Identification of proteolytic degradation of recombinant protein
Question: I purified a recombinant protein and analyzed it by 1D SDS PAGE. In addition to the intact protein (52...
Assessing stability of protein drug substance & formulated drug product
After protein purification, an important issue is the stability of a protein drug substance and formulated drug product. Stability assays...
Host Cell Protein monitoring & control in process development
Mass spectrometry based Host Cell Protein identification and quantification Here the Mass Spec Host Cell Protein (HCP) assay is applied for...