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ForteBio Interactions Newsletter Biosensor photo

SUMMER 2011    VOLUME 4    ISSUE 2

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NEW Dip and Read™ Anti-Mouse IgG (Fc) Capture (AMC) Biosensors

Weilei Ma, Senior Scientist, ForteBio

Monoclonal antibodies are key tools for basic research as well as for diagnosis and treatment of human diseases. Therapeutic monoclonal antibodies approached $50 billion in worldwide sales in 2010, and six of the current top twenty pharmaceuticals are monoclonal antibodies.

The expanding demand for high-quality antibodies with better specificities has resulted in a significant improvement in traditional hybridoma production methods, allowing production of a large number of antibodies against a target antigen. This has created an increasing demand for screening methods that characterize antibody-antigen interactions.

With the rapidly increasing pace of screening also comes the need to more fully characterize the antibodies at an earlier stage to improve the efficiency of the antibody selection process. The traditional approach of using end-point ELISA techniques to identify high-affinity antibodies provides limited information and suffers complications due to interference by tags. By contrast, label-free screening methods provide kinetic information on antibody-antigen interactions that lead to reliable estimation and ranking of antibodies in their affinity for the antigen.

ForteBio’s Octet platform provides a microfluidics-free, higher throughput, label-free kinetics platform for screening antibodies in complex samples against target antigen. By analyzing directly in crude media without costly and time-consuming purification steps, the Octet platform saves valuable time and effort.

With the recent launch of the Dip and Read™ Anti-Mouse IgG Fc Capture (AMC) biosensors, kinetic characterization of macromolecular interactions of mouse antibodies and other mouse Fc-containing proteins against target analytes is easier than ever. Cost-effective regeneration of the biosensors and the ability to directly immobilize mouse Fc-containing proteins from crude matrices make the AMC biosensor extremely useful in high-throughput applications.

AMC biosensors provide a flexible platform for evaluating the kinetics between mouse Fc-containing proteins and their analytes.

AMC biosensors enable:

  • Complete kinetic analysis (ka, kd and KD) between mouse Fc-containing proteins and target analytes
  • Off-rate ranking of hybridoma and stable cell-line supernatants
  • Epitope binning/mapping (from crude or purified samples)
  • Tracking product integrity by measuring ka, kd and KD during:
    • Upstream fermentation
    • Downstream harvest and purification
    • Post-derivization (pegylation)
    • Formulation development

AMC biosensors deliver:

  • Simplified assay development — validated capture format eliminates need for biotinylation or purification of antibodies from crude matrix.
  • Ease of use — a high-affinity anti-mouse antibody conjugated to the biosensor is readily available for off-the-shelf use.
  • Quality — a high-quality biosensor verified by ForteBio for use in kinetic analysis.

The AMC biosensors are pre-immobilized with a high affinity antibody against the Fc portion of mouse IgG. This antibody can capture and immobilize mouse IgG (mIgG) and other Fc-containing ligands to produce a stable surface suitable for interaction analysis. The capture surface is particularly suited for immobilizing mIgG from cell culture supernatants and other complex mixtures in which biotinylation is not an option.

AMC biosensors streamline the antibody screening workflow by enabling immobilization of mouse Fc-containing proteins on the biosensor directly from a crude or purified matrix. No purification or biotinylation steps are required, thereby facilitating high throughput screening methods.

Mouse IgG subtypes IgG1, IgG2a and IgG2b are recommended for use with AMC biosensors; IgG3 should be evaluated on a case-by-case basis. The AMC biosensor is ready for use on all Octet systems.

For more information, visit the AMC biosensor web page and download the AMC biosensor datasheet and technical note.

7 Years and 4 Million Biosensors Later…

Christopher M. Silva, Vice President, Marketing

Over the last seven years, ForteBio and its Octet® platform have traveled an exciting journey with our customers. With their support, ForteBio, based in Menlo Park, CA, with subsidiaries in London and Shanghai, has become the second-leading — and fastest-growing — provider of label-free analysis tools for the pharmaceutical and biotechnology research fields, according to leading independent market analysis firms.

We launched our first product, the Octet QK system for label-free, real-time detection and analysis of protein-protein interactions, at the Antibody Engineering conference in San Diego in 2005. The revolutionary Octet platform accelerates protein and antibody discovery and development by generating real-time quantitative and kinetics results in higher-throughput formats, quickly and easily. Our ready-to-use, Dip and Read™ disposable biosensors enable researchers to measure concentrations and kinetic rates of critical samples, even in crude matrices, with unprecedented ease of use and cost-effectiveness.

Since then, customer response to our technology and products — including our broadening menu of 13 “off-the-shelf” biosensors — has been overwhelming. To date, we have shipped more than 4 million biosensors and, by 2010, more than 100 literature citations referenced our technology, signaling its strong adoption.

ForteBio’s web site hosts many end-user presentations from scientific conferences detailing productivity gains achieved via Octet. In addition to employing our off-the-shelf biosensor chemistries, users continually develop compelling new applications for our technology by immobilizing a ligand of interest to Streptavidin or Amine-reactive biosensors. Some of these applications include contaminant testing, vaccine development and virus-like particle analysis.

We are constantly working to improve and expand the Octet platform. In March 2008, we launched our second-generation system, Octet RED, whose extended sensitivity and reduced noise enabled small molecule drug discovery applications such as interaction analysis of fragment screening and peptides analysis. The third-generation Octet 384 systems further advanced the platform with automation capabilities and unattended operation in both 96- and 384-well plate formats. In 2010, biosensor re-racking was added to the product line, augmenting workflow flexibility and decreasing running costs.

The wide range of microfluidic-free Dip and Read™ biosensors is key to the Octet platform’s ease of use and fast time to results. For example, Protein A biosensors have facilitated antibody titer in cell line development with quantitation of 96- or 384-well sample plates in minutes, offering a strong alternative to ELISA and HPLC assays, which are labor-intensive and have a lag in time-to-result. Streptavidin biosensors allow researchers to immobilize custom molecules and conduct tailored quantitation, kinetic and affinity measurements.

ForteBio’s biosensor-based solution has two components: a low cost per data point, enabling customers to adopt the Octet platform broadly; and complete solution kits and methods, such as the Host Cell Protein and Residual Protein A assays which include biosensors and requisite reagents. The Octet system has also become a strong tool to complement or replace SPR (surface plasmon resonance) techniques, in which instrument running cost and throughput inefficiencies hinder research productivity. In fact, many Octet users tell us they routinely run antibody screening, epitope binning and affinity characterization studies — applications typically conducted with SPR — using the Octet system.

Our customers have also strongly adopted our recently launched biosensor chemistries and other enhancements including Protein G, Protein L and anti-murine biosensor chemistries, as well as new software tools in Octet Software version 7.0.

ForteBio continues to experience tremendous success, having achieved double-digit growth over the last few years. We could not have accomplished this without the ongoing partnership and support of our valued customers. We thank them and look forward to much continued success together in the coming years.