Dr. Thomas FladHead of Business Development
South Germany, DACH Region
A critical task in biologics manufacturing is the control of process-related impurities such as host cell proteins (HCPs), which co-purify with the drug substance and are known for adverse effects (e.g., immunogenicity). For decades, the method of choice to detect host cell proteins has been an immunoassay based on polyclonal antisera raised against a population of HCPs. However, there are some inevitable risk factors (e.g., antigens, animals, etc.) associated with this approach, and the final selectivity and sensitivity of the HCP assay strongly depends on the preparation work and materials used at the start.
Combining tools from proteomics, bioinformatics, protein synthesis and immunology, effectively minimizes black box elements, provides targeted enhancement of coverage, and maximizes the performance of HCP assays.
PPS is offering services in:
The process is tailored to your needs because every client’s requirements are different.
For demonstration of specificity of the reagents used in the ELISA, either high resolution 2D PAGE of respective antigens (e.g. whole cell lysate, DSP fraction) or immuneaffinity purification (IAC) is performed.
A well accepted approach is the testing by 2D PAGE. Total HCPs are visualized by sensitive silver staining. In parallel a second 2D PAGE gel is subjected to Western blotting to visualize all HCPs recognized by respective antisera. These patterns are compared and visualized by overlay. Ideally, all HCPs visualized by silver staining are also recognized in the Western blot experiment, which would mean there are no detection gaps of the used antiserum.
A more advanced approach is IAC; where the ELISA antibodies are coupled to magnetic beads and incubated with e.g. harvest samples. HCPs that bind specifically to the coupled antibodies are identified by mass spectrometry (LC-MS). A list with covered and non-covered proteins will provide the specificity of the ELISA antibodies. The advantage of this approach is the evaluation of native proteins, which is a closer ELISA reality than SDS-PAGE.
If detection gaps occur, we recommend usage of our HCP-GAPex™ services.
Application example for qualification of HCP antiserum.
Protagen Protein Services (PPS) is a world leading CRO and recognized expert for analytical services in protein science regarding characterization, method development, validation and routine testing of antibodies, proteins, vaccines and other formates of biopharmaceuticals. Our sites are equipped with modern, state-of-the-art equipment for the analytical characterization of biopharmaceuticals regarding structure, purity, chemical modification, aggregation, particle formation, thermal stability e.g.. We offer service modules for analytcal support from research to approval regarding:
Protagen Protein Services (PPS) is a world leading CRO and recognized expert for analytical services in protein science. More than 20 years of market experience and the comprehensive spectrum of validated analytical methods ensure the highest quality for customers in the pharmaceutical, biotech and life science industry.
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