Host cell proteins (HCPs) are a major class of process-related impurities generated during biopharmaceutical manufacturing. Although the vast majority of these proteins are removed from drug substrates during downstream purification, residual HCPs may remain in drug products, result in immunogenicity risk even at the lowest concentrations. Furthermore, co-purification of proteolytically active HCPs compromises protein product yield, potency, and stability. There are also some HCPs may cause excipient degradation and particle formation. Therefore, regulators consider HCPs content to be a critical quality attribute. Manufacturers must quantitatively analyze the residual HCP in process and drug products to ensure the consistency of the purification process and the safety of the final product, while enzyme-linked immunosorbent assay (ELISA) is the most used method.

CHO HCP (Host Cell Protein) residue assay kit is designed to detect host cell protein (HCP) residues from the manufacturing process of biologics based on Chinese hamster ovary (CHO) cell CHO-K1 cell line. Specific antibodies can recognize and detect more than 80% of HCP molecules, including low and high molecular weight species. The assay kit can be used in the early or late process development stages of projects using CHO-K1 expression system, and quality control labs. It can analyze the removal efficiency of HCP during the process development process, as well as the quality control for product release test.

Application

The CHO HCP assay kit from Duoning adopts one-step enzyme-linked immunosorbent assay method. Samples containing HCP can reacted simultaneously with HRP-labeled goat anti-CHO-K1 antibody and anti-CHO-K1 antibody coated on microtiter plate. Finally, a sandwich complex of solid-phase antibody-HCP-labeled antibody is formed. Unbound antigen and antibody can be removed by washing the plate. After the TMB substrate was added to the wells for sufficient reaction, termination solution was added to terminate color development, and the OD values of the reaction solution at 450 nm and 650 nm were analyzed with a microplate reader. The value of OD 450 nm - OD 650 nm is positively correlated with the HCP content in the solution, and the HCP concentration can be calculated according to the standard curve.

Product Feature

Higher coverage rate of 81% (using 2D Gel/Western Blot assay): The detection antibody used by Duoning HCP Assay Kit has a wider recognition efficiency for host cell proteins of different sizes and isoelectric points. After 2D electrophoresis and Western Blot assay, the coverage rate can reach > 80%.

Case Study

The blue box in the figure is the host cell proteins recognized by both Duoning kit and other commercial kits on the market, while the red box is the additional host cell proteins recognized by the Duoning Kit.

Good linearity: The measurement of CHO-K1 host cell protein shows that Duoning HCP assay kit provides good linearity in a wide range (3 ng/mL-100 ng/mL).

Excellent solvent compatibility and assay specificity:

Good precision and accuracy: The repeatability and precision of the kit were investigated at three different sample concentrations: low, medium, and high. The results showed that the kit had good repeatability and accuracy under different concentrations and meet requirements of quality control standards.

Good sensitivity and lowest quantification limit: The operation index of the kit was investigated at the lowest quantification limit (3 ng/mL), and the results showed that the kit still had good signal-to-noise ratio, precision, and accuracy at the lowest quantitation limit.

Ordering Information