Assays

North, South, East, and West

Electrophoresis is the basis of all blotting methods, and BPI Lab covered it last month (1). Electroblotting is a method for transferring electrophoretically separated proteins or nucleic acids onto a polyvinylidene fluoride (PVDF) or nitrocellulose membrane for permanence using electric current and a transfer buffer solution. This allows for analysts to further study them using probes, ligands, or stains. Capillary blotting is a variation designed to work with capillary electrophoresis. After electrophoresis the following are stacked in cathode-to-anode order: a…

Enabling Technologies

Many technological advancements in recent years have enabled companies to shorten time to market, to better understand their manufacturing processes, and to characterize their products well. In BPI’s December 2013 issue (pages 47–50), I reported on the first half of an informal reader survey about those technologies, with commentary from some survey participants and others. This month concludes with my examination of analytical, formulation/fill–finish, and facilities technologies. Analytical Technologies After writing several installments of our new “BPI Lab” series this…

Ready-to-Use Cryopreserved Primary Cells

Abiological measurement of drug activity is perhaps the most critical step in the series of tests required for product release both for clinical trials and the market. This evaluation plays an important role in the stability assessment of drug candidates. According to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) Q6B document, measurements of biological activity can be performed in defined animal models that demonstrate a measurable physiological change in response to…

Nucleic Acid Impurity Reduction in Viral Vaccine Manufacturing

Commercial-scale viral vaccine manufacturing requires production of large quantities of virus as an antigenic source. To deliver those quantities, a number of systems are used for viral replication based on mammalian, avian, or insect cells. To overcome the inherent limitations in production outputs with serial propagation of cells, mammalian cells can be immortalized, which increases the number of times they can divide in culture. Modifications that immortalize cells are typically accomplished through mechanisms similar to those converting normal cells to…

Assay Acceptance Criteria for Multiwell-Plate–Based Biological Potency Assays

For most biopharmaceuticals, potency is assessed in a bioassay by comparing dose–response curves of the test material and a reference standard. As with all analytical techniques, such assays require criteria by which their execution can be judged objectively to be valid, regardless of whether the desired or expected result is obtained for the test sample. PRODUCT FOCUS: BIOLOGICSPROCESSFOCUS: R&D, QCWHO SHOULD READ: PRODUCT AND PROCESS DEVELOPMENT, ANALYTICAL, QCKEYWORDS: IMMUNOASSAYS, POTENCY ASSAYS, PRODUCT RELEASE, REFERENCE STANDARDS, CONTROL SAMPLES, SAMPLE ACCEPTANCELEVEL: ADVANCED…

Mathematical Model for Production of Recombinant Antibody 14D9 By Nicotiana tabacum Cell Suspension Batch Culture

Transgenic plants are increasingly considered a competing system for producing high-value recombinant proteins for biomedical and industrial purposes at affordable costs (1). Researchers have shown that molecular farming (or biopharming) is a secure technology that is capable of rendering valuable recombinant proteins free of toxins and animal pathogens in a relatively short time (2,3,4,5,6). Scientists have also demonstrated that most recombinant antibodies produced in plants maintain their functional properties (substantial bioequivalence) as well as do those produced in mammalian cell…

Quality Risk Assessment and Management Strategies for Biopharmaceutical Companies

You’ve probably been hearing a lot about risk assessment in recent months. Indeed, some 15 times more articles have been printed referencing the concept over the past year relative to a 12-month period just three years ago. That truly represents a geometric progression. Unfortunately, very few authors have been able to disambiguate the different methods or provide insight into this time-tested, multiple-industry philosophy that at its core uses good science to make better decisions. When we undertake the challenge to…

Robots in the Laboratory

Whether cell-based or molecular biology focused, most assays performed in biopharmaceutical laboratories involve liquid solutions. Increasingly, automated liquid handlers (laboratory robotics) are demonstrating utility in these labs, especially for high-throughput screening and optimization of cell culture media, chromatography conditions, formulations, and so on. Some experts say that screening 100,000 samples/day will soon become routine. But the robots haven’t condemned all manual pipettes to the trash heap — far from it. With multichannel and electronic pipettes improving throughput and reproducibility of…

Biological Assay Qualification Using Design of Experiments

In 2012, the United States Pharmacopeia (USP) published a complementary set of three guidance documents on the development, analysis, and validation of biological assays (1,2,3). USP chapter recommends a novel, systematic approach for bioassay validation using design of experiments (DoE) that incorporates robustness of critical parameters (2). Use of DoE to establish robustness has been reported (4,–5), but to our knowledge its use in qualification or validation protocols for assessing assay accuracy, precision, and linearity is not described in literature.…

High-Throughput Chromatography Screenings for Modulating Charge-Related Isoform Patterns

Monoclonal antibodies (MAbs) are an important class of biopharmaceuticals and are widely used to treat a variety of diseases such as cardiovascular diseases, cancer, and blood disorders. Antibodies are very complex proteins that show a high degree of microheterogeneities, including charge-, hydrophobicity- and size-related variances (1). Such variants can arise during any stage in a manufacturing process or storage as a result of enzymatic or nonenzymatic processes (2). Particular antibody variants that may affect the in vitro and in vivo…