We develop all the required product-specific release and stability-determining assays for your recombinant protein.
There may be a wish to rush conclusions, often resulting in treatment of biochemical analysis of proteins as trivial or superfluous. Unfortunately, this attitude may lead to irreproducible or misleading results, which can backfire at the advanced stages of process or product development with potentially large financial consequences. With more and more complex large molecules under investigation (e.g. integral membrane proteins, heavily glycosylated ion proteins or various antibody formats) the importance of having reliable, accurate and sensitive assays is of paramount importance. The correct interpretation of many biophysical/structural characterization experiments relies on three assumptions:
We are working on many different projects every year, and quality control is ingrained into our thinking, procedures and actions. Without a doubt, a meticulous and critical attitude towards testing on the quality of protein preparations significantly increases the chances of success in subsequent experiments.
For analysis of critical parameters of manufactured material, we use our product-specific and generic assays such as ELISAs, to evaluate titer and productivity of cells or analytical protein-A-based assays to evaluate antibody titer and productivity. We run standard biochemical assays including SDS-PAGE (reduced, non-reduced, glycosylated and de-glycosylated) and western blot analyses to assess product quality, purity and in the case of the latter, also assess the specificity. To determine potency, we typically run in vitro and cell-based assays. For purity determination, we deploy residual protein-A analyses and use HPLC-SEC to determine the ratio between monomers and aggregates. We quantify charge variant using IEX-HPLC and perform routine IEF analyses to assess isomers and glycosylation degree. We determine sialic acid content and perform N-glycan analyses. For further purity analyses, we run host cell protein and host cell DNA analyses and determine endotoxin levels. In addition to our set of ready-to-go assays based on our SOP system, we are well equipped to develop new assays and have an excellent track record in successfully transferring customer-developed assays for further development, optimization, qualification and validation.