Recombinant Antibody-Producing Stable CHOK1 Pool Stability Study.

Mammalian cell line stability is an important consideration when establishing a biologics manufacturing process in the biopharmaceutical and diagnostics (IVD) industries. Traditional Chinese hamster ovary (CHO) cell line development methods use a random integration approach that requires transfection, selection, optional amplification, screenings, and single-cell cloning to select clones with acceptable productivity, product quality, and genetic stability. Site-specific integration reduces these disadvantages, and new technologies have been developed to mitigate risks associated with genetic instability.

Antibody engineering to generate anti-tumor-associated glycoprotein 72 mouse recombinant CC49 IgG with improved solubility, purity, and thermal stability.

Tumor-associated glycoprotein 72 (TAG-72) is a mucin that is overexpressed heterogeneously on the surface of cancer cells, and is a potential target for immunotherapies for various cancer types. As a tumor marker, TAG-72 is measured with the cancer antigen (CA) 72-4 immunoassay. The murine monoclonal antibody (mAb) CC49 is a second-generation IgG that targets an antigen on TAG-72; however, CC49 has an unfavorable propensity to aggregate, which results in antibody impurity, instability, and low solubility and thus low potency and efficacy for therapeutic and diagnostic applications.

Validation of the novel GLAS algorithm as an aid in the detection of liver fibrosis and cirrhosis based on GP73, LG2m, age, and sex.

Background: Diagnosis of liver disease at earlier stages can improve outcomes and reduce the risk of progression to malignancy. Liver biopsy is the gold standard for diagnosis of liver disease, but is invasive and sample acquisition errors are common. Serum biomarkers for liver function and fibrosis, combined with patient factors, may allow for noninvasive detection of liver disease.

Pre-analytical considerations in the development of a prototype SARS-CoV-2 antigen ARCHITECT automated immunoassay.

Objectives: To evaluate pre-analytical challenges related to high-volume central laboratory SARS-CoV-2 antigen testing with a prototype qualitative SARS-CoV-2 antigen immunoassay run on the automated Abbott ARCHITECT instrument.

Methods: Contrived positive and negative specimens and de-identified nasal and nasopharyngeal specimens in transport media were used to evaluate specimen and reagent on-board stability, assay analytical performance and interference, and clinical performance.

Results: TCID50/mL values were similar for specimens in various transport media.

Development of an automated chemiluminescent immunoassay for cancer antigen 72-4 and the evaluation of its analytical performance.

Objectives: Cancer antigen (CA) 72-4 assay is widely used for monitoring gastric and ovarian cancers. The antigen is a mucin-like, tumor-associated glycoprotein known as TAG-72. It has been identified and characterized using two different monoclonal antibodies, CC49 and B72.

Development of a new automated IL-6 immunoassay.

Objectives: Quantitative detection of interleukin-6 (IL-6) in serum and plasma can help monitor immune responses and the development of acute inflammation to guide patient management. We developed an IL-6 immunoassay for use with the automated ARCHITECT system for detecting an increase in the inflammatory response.

Methods: Immunized mouse sera were tested and selected B-cells were harvested for fusion with myeloma cells.

Myeloma-Derived Light Chain Paired with a Diagnostic Monoclonal Antibody Hinders Immunoassay Performance.

Monoclonal antibodies are widely used as the capture and detection reagents in diagnostic immunoassays. In the past, myeloma fusion partners expressing endogenous heavy and/or light chains were often used to generate hybridoma cell lines. As a result, mixed populations of antibodies were produced that can cause inaccurate test results, poor antibody stability, and significant lot-to-lot variability.

Generation of human neutrophil gelatinase-associated lipocalin monoclonal antibodies for use in ARCHITECT® assay.

Development of a robust immunoassay requires the selection of monoclonal antibodies with desired properties. These properties generally include kinetics parameters such as on-rate and off-rate (i.e.

Characterization of antibodies elicited by XMRV infection and development of immunoassays useful for epidemiologic studies.

Background: Xenotropic Murine Leukemia Virus-related Virus (XMRV) is a human gammaretrovirus recently identified in prostate cancer tissue and in lymphocytes of patients with chronic fatigue syndrome. To establish the etiologic role of XMRV infection in human disease requires large scale epidemiologic studies. Development of assays to detect XMRV-specific antibodies would greatly facilitate such studies.

Generation and characterization of chimeric antibodies against NS3, NS4, NS5, and core antigens of hepatitis C virus.

Mouse-human chimeric antibodies (cAbs) against hepatitis C virus (HCV) core, NS3 (nonstructural), NS4, and NS5 antigens were developed as quality control (QC) reagents to replace the use of human sera/plasma for Abbott HCV immunoassays. The cAb retains the mouse monoclonal antibody (MAb) specificity and affinity but still reacts in the existing HCV assay format, which measures human anti-HCV immunoglobulin. Mouse heavy-chain (V(H)) and light-chain (V(L)) variable regions of anti-HCV core, NS3, NS4, and NS5 antigens were PCR amplified from hybridoma lines and then cloned with human IgG1 heavy-chain (C(H)) and light-chain (C(L)) constant regions, respectively.