Chris D. Webb

Detection of single micron-sized magnetic bead and magnetic nanoparticles using spin valve sensors for biological applications

We have fabricated a series of highly sensitive spin valve sensors on a micron scale that successfully detected the presence of a single superparamagnetic bead (Dynabeads M-280, 2.8 μm in diameter), and thus showed suitability for identifying biomolecules labeled by such magnetic beads. By polarizing the magnetic microbead on a spin valve sensor with a dc magnetic field and modulating its magnetization with an orthogonal ac magnetic field, we observed a magnetoresistance (MR) signal reduction caused by the magnetic dipole field from the bead that partially cancelled the applied fields to the spin valve. A lock-in technique was used to measure a voltage signal due to the MR reduction. A signal of 1.2 mV rms or 5.2 mΩ of resistance reduction was obtained from a 3 μm wide sensor and a signal of 3.8 mV rms or 11.9 mΩ from a 2.5 μm wide sensor. Micromagnetic simulations were also performed for the spin valve sensors with a single bead and gave results consistent with experiments. Further experiments and simula...

Suspension bead array branch migration displacement assay for rapid STR analysis

STR analysis is commonly used in forensic and genetic studies. STRs are currently discriminated based on size, primarily by gel‐ and column‐based approaches. Hybridization‐based approaches have the potential to allow high‐throughput analysis of STRs; however, development of such approaches has been limited by the difficulty in discriminating between STRs of similar length. We have recently described several innovations to enable STR analysis using an array‐based hybridization approach for high‐ throughput STR analysis. Here we extend that approach by incorporating the array into microspheres and adding a discriminatory branch migration displacement step. This microsphere‐based platform uses Luminex xMAP technology and improves the sensitivity, selectivity, and speed of the assay. We demonstrate the feasibility, speed, and reliability of the assay for STR detection by correctly analyzing two STR loci in 20 forensic DNA samples of known STR type. The multiplex, bead‐based approach provides a high‐throughput and more portable STR analysis.

The CTSA Consortium's Catalog of Assets for Translational and Clinical Health Research (CATCHR).

The 61 CTSA Consortium sites are home to valuable programs and infrastructure supporting translational science and all are charged with ensuring that such investments translate quickly to improved clinical care. Catalog of Assets for Translational and Clinical Health Research (CATCHR) is the Consortiums effort to collect and make available information on programs and resources to maximize efficiency and facilitate collaborations. By capturing information on a broad range of assets supporting the entire clinical and translational research spectrum, CATCHR aims to provide the necessary infrastructure and processes to establish and maintain an open‐access, searchable database of consortium resources to support multisite clinical and translational research studies. Data are collected using rigorous, defined methods, with the resulting information made visible through an integrated, searchable Web‐based tool. Additional easy‐to‐use Web tools assist resource owners in validating and updating resource information over time. In this paper, we discuss the design and scope of the project, data collection methods, current results, and future plans for development and sustainability. With increasing pressure on research programs to avoid redundancy, CATCHR aims to make available information on programs and core facilities to maximize efficient use of resources.

The CTSA Consortium's Catalog of Assets for Translational and Clinical Health Research (CATCHR): The Ctsa Consortium's Catchr

The 61 CTSA Consortium sites are home to valuable programs and infrastructure supporting translational science and all are charged with ensuring that such investments translate quickly to improved clinical care. Catalog of Assets for Translational and Clinical Health Research (CATCHR) is the Consortiums effort to collect and make available information on programs and resources to maximize efficiency and facilitate collaborations. By capturing information on a broad range of assets supporting the entire clinical and translational research spectrum, CATCHR aims to provide the necessary infrastructure and processes to establish and maintain an open‐access, searchable database of consortium resources to support multisite clinical and translational research studies. Data are collected using rigorous, defined methods, with the resulting information made visible through an integrated, searchable Web‐based tool. Additional easy‐to‐use Web tools assist resource owners in validating and updating resource information over time. In this paper, we discuss the design and scope of the project, data collection methods, current results, and future plans for development and sustainability. With increasing pressure on research programs to avoid redundancy, CATCHR aims to make available information on programs and core facilities to maximize efficient use of resources.

The CTSA Consortium’s CATCHR (Catalog of Assets for Translational and Clinical Health Research)

The 61 CTSA Consortium sites are home to valuable programs and infrastructure supporting translational science and all are charged with ensuring that such investments translate quickly to improved clinical care. Catalog of Assets for Translational and Clinical Health Research (CATCHR) is the Consortiums effort to collect and make available information on programs and resources to maximize efficiency and facilitate collaborations. By capturing information on a broad range of assets supporting the entire clinical and translational research spectrum, CATCHR aims to provide the necessary infrastructure and processes to establish and maintain an open‐access, searchable database of consortium resources to support multisite clinical and translational research studies. Data are collected using rigorous, defined methods, with the resulting information made visible through an integrated, searchable Web‐based tool. Additional easy‐to‐use Web tools assist resource owners in validating and updating resource information over time. In this paper, we discuss the design and scope of the project, data collection methods, current results, and future plans for development and sustainability. With increasing pressure on research programs to avoid redundancy, CATCHR aims to make available information on programs and core facilities to maximize efficient use of resources.