Answer: Generic kits are broadly used for the measurement of HCPs in biologicals during the downstream process. However, for the later stages, process-specific HCP ELISAs are recommended since they are far more specific than generic kits. The establishment of customized HCP ELISAs is a large project and should be well-planned. BioGenes has comprehensive experience in the development of process-specific HCP ELISAs. Every customer has the opportunity to consult our scientific team before starting the development of an HCP ELISA.
The development of process-specific HCP ELISAs is divided into three phases:
- Mock HCP antigen preparation phase
- Antibody generation & antibody characterization phase
- Assay development, qualification & pre-validation phase
The first step of a customized ELISA development is the preparation of Mock HCP material for immunization, which only contains the process-related proteins without the final drug. Since smaller proteins tend to be less immunogenic, fractionation of total HCPs, followed by separate immunization of total and low molecular weight HCPs, is recommended. We suggest pre-testing the Mock HCP material to an early downstream processing (DSP) sample by 2D DIGE to ensure the suitability of the Mock HCP material before immunization.
In the antibody generation phase, we recommend the immunisation of two different animal species (rabbit and goat) simultaneously, because in our experience, each project is unique and thus it can’t be determined which animal specie is suitable for the best antibody generation. For characterization of the generated antibodies, a part of the antiserum is affinity purified using immobilized total Host Cell Protein material. The test antibodies from both species are characterised by 1D Western blot and tested in a preliminary ELISA setup by measuring DSP samples from different purification steps. This enables the selection of the most suitable animal species. The selected species is further immunized to generate a sufficient amount of antiserum/ antibodies needed for HCP measurement for approximately 10 - 15 years.
We recommend the affinity purification of the complete antiserum amount using immobilized total HCP material. For the coverage analysis of the final anti-HCP antibody, we offer fluorescence-based 2D Western blot analysis and immunoaffinity chromatography (IAC) in combination with 2D DIGE and mass spectrometry, cooperating with one of our partners.
In the last stage, the process-specific Host Cell Protein ELISA will be developed in a buffer matrix by employing also a relevant process sample (e.g. highly purified final drug substance, subsequently qualified using again DSP samples of different purification levels and eventually pre-validated according to the ICH guideline Q2 (R1).
Each phase of the development process can be individually extended by our comprehensive service portfolio or stopped at any time and only the executed work will be charged. The development of a process-specific ELISA is time-consuming and might take 1 to 1.5 years. Thus, BioGenes recommends getting in touch with us at an early stage to design and coordinate your process-specific Host Cell Protein ELISA project with our scientific experts.