Tag: <span>igg</span>

This article describes methods for dissociation of aggregates and antibody-contaminant complexes on hydroxyapatite. The application of decomplexing washes weakens complex stability. Because of its high affinity for apatite calcium, the DNA component of complexes is attracted more strongly to apatite calcium than it is to the antibody. The combination of weakened complexation and strong attraction to apatite calcium apparently allows the apatite to actively extract DNA from the complexes. Once bound to the apatite, DNA cannot rejoin the antibody so that when the antibody is eluted, the DNA remains behind. Whereas conventional application of hydroxyapatite supports effective aggregate removal, the present method dissociates non-covalent aggregates into native antibody. Non-product contaminant complexes are also dissociated and removed more effectively. The method works with both IgG and IgM. Data suggest that host cell DNA fragments are the nucleation centers for antibody aggregate formation…

Biologics Production

Hybridoma cell lines are highly unpredictable and often, an unreliable source of important antibodies of national security interest. There is an urgent need to convert antibody production from these cell lines into robust, recombinant platforms that can reliably produce large quantities of antibody on demand, and abandon methods based on murine ascites production. This work describes the use of lentiviral vectors, Chinese hamster ovary (CHO)-K1 cells, and high-density perfusion cultures for antibody production. Cell line development was rapid, high insertion copy numbers were achievable, and the heavy/light chain ratios could be rapidly optimized. The mammalian cells provided an appropriate environment for IgG folding and obviated the difficult purification steps such as removal of endotoxins, refolding, or dealing with abnormal post-synthetic modifications common to other production systems. We found that even in the absence of an optimized cell line, in high-density cultures, routine productivities in the 1–5 g/L range were achieved. As expected, productivity was independent of the performance of the original hybridomas. We conclude that the lentiviral vector system can achieve high copy numbers of immunoglobulin genes with optimized heavy and light chain ratios to appropriately assemble and secrete the immunoglobulins, achieving high productivity. This observation suggests that substantial advances can be made by selecting and optimizing the cell line used for immunoglobulin production. The lentiviral vector-based method of antibody production offers substantial improvements over traditional murine ascites-based antibody production in terms of reliability, productivity, and cumulative cost—if the antibody need exceeds 1–3 grams within the shelf life of the product…

Biologics Production

Immunoaffinity chromatography is an indispensable purification tool. However, its use has been limited by cost, purification cycle numbers, and storage requirements. Therefore, authors speculated that a possible solution to these problems could be CB.Hep-1 monoclonal antibody (mAb)-immunosorbent lyophilization. This study sought to assess the impact of the CB.Hep-1 mAb quantification by enzyme-linked immunoadsorbent assay and the CB.Hep-1 mAb-immunosorbent lyophilization process for its impact on hepatitis B virus surface antigen purification for pharmaceutical use. Study results found that CB.Hep-1 mAb lyophilization did not affect mAb purity and antigen recognition capacity. CB.Hep-1 mAb-immunosorbent lyophilization did not modify volume-weight factor, infrared spectrum, particle-size distribution, particle density and viscosity, antigen adsorption capacity, antigen elution capacity, antigen recovery, antigen purity, gamma immunoglobulin (IgG) leakage, and purification cycle number. Therefore, the lyophilized CB.Hep-1 mAb and CB.Hep-1 mAb-immunosorbents can be successfully used for hepatitis B vaccine production…

Analytics Biologics Production