Senior Member of the Technical Staff
Biotechnology and Bioengineering Department
(925) 294-6847 / rmeaghe@sandia.gov
Dr. Robert Meagher is a staff member in the Biotechnology and Bioengineering department at Sandia National Laboratories. Dr. Meagher has been involved in numerous projects within the Biotechnology and Bioengineering department (formerly known as the Biosystems Research department) and has collaborated with researchers in the Microfluidics, Energy Systems, Combustion Chemistry, and Biomolecular Interfaces departments. Dr. Meagher’s general project areas include microscale protein electrophoresis, microscale protein purification, droplet microfluidics, and single-cell bacterial analysis.
Dr. Meagher earned a bachelor’s degree in chemical engineering at the Massachusetts Institute of Technology (MIT) in 1997, followed by a master’s degree in chemical engineering practice from MIT in 1998. During this period, Dr. Meagher performed research on the thermodynamics of phase transitions in mixed surfactant solutions and interned in the petrochemical, automotive, and semiconductor industries. He then spent two years as a research engineer in petroleum refining with Amoco (later BP), where he specialized in process simulation and pilot-scale catalyst testing.
In 2000, Dr. Meagher began graduate studies in the Department of Chemical Engineering at Northwestern University, where he specialized in microchannel electrophoresis. Under the direction of Annelise Barron, he developed a novel bioconjugate technique for electrophoretic separations of DNA (including DNA sequencing and DNA “fingerprinting” analyses) without a gel or sieving matrix. Dr. Meagher also developed and tested polymeric coatings for glass microchannel surfaces and performed solid-phase synthesis of peptides and peptide-like oligomers called peptoids. Dr. Meagher began his current postdoctoral appointment at Sandia after receiving his Ph.D. in chemical engineering from Northwestern University in 2005.
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Development of a point-of-care device for detecting exposure to biological toxinsWe are developing electrophoretic immunoassays to detect protein biotoxins, including ricin, Shiga toxin, Staphylococcal enterotoxin B, and botulinum. Our goal is to produce a low-cost, portable, diagnostic device suitable for rapidly diagnosing toxin exposure in the case of a bioterror attack. Team members include Anson Hatch, Greg Sommer, Ying-Chih Wang, Ron Renzi, and Anup Singh. |
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Purification of proteins by microfluidic two-phase extractionWe have demonstrated a technique for “micropreparative” rapid purification of small amounts of recombinant protein using laminar-flow aqueous two-phase extraction. To extend the range of possible protein targets, the system works with a variety of genetic fusion tags, including aromatic-rich partition tags, as well as common affinity tags (e.g., His-tag). The process is designed for high-throughput protein expression experiments, such as screening enzyme variants for biofuel production. Team members include Yooli Light and Anup Singh. |
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Identification of bacteria in complex samples by fluorescent in situ hybridization (FISH)Because many clinically or environmentally relevant species of bacteria are difficult or impossible to cultivate in the laboratory, it is difficult to accurately determine the makeup of complex samples. We are developing a microfluidic device to perform FISH, a common and powerful technique that uses fluorescent probes specific for genetic targets on the 16S rRNA to identify specific types of bacteria. Our microfluidic approach automates the process, reduces analysis time, reduces the use of reagents, and will be integrated with optical cell-sorting techniques developed at Sandia. Collaborators include Yooli Light, Julie Kaiser, and Anup Singh. |
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Analysis of cells and biomolecules in picoliter dropletsThe field of “droplet microfluidics” or “digital microfluidics” is potentially interesting for high-throughput screening applications, including enzyme engineering and single-cell analysis. Using a T-junction with a microfabricated micropore, we segment an aqueous stream into a series of highly uniform, picoliter-volume droplets or “containers,” which are stabilized with surfactants and are suitable for performing biochemical assays. Applications include mRNA profiling of single bacterial cells, as well as high-throughput expression and screening of cellulose-degrading enzymes. Collaborators include Yooli Light, Masood Hadi, Suruchi Anand, Thomas Perroud, Ken Patel, and Anup Singh. |
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Microchannel electrophoresis with single-molecule detectionWe have coupled microfluidic protein separations with the unique time-resolved confocal fluorescence microscope developed by Carl Hayden at Sandia’s Combustion Research Facility. This microscope, which uses a picosecond-pulsed laser and custom detection hardware, enables us to determine the fluorescence lifetime and wavelength of each photon collected. The microscope also provides us with the capability to perform fluorescence correlation spectroscopy (FCS), fluorescence cross-correlation spectroscopy (FCCS), and a variety of temporal and spectral gating techniques. These capabilities, which have been used to study protein–protein and antibody–toxin interactions, are expected to be useful for a variety of sophisticated diagnostics. Collaborators include Carl Hayden, Thomas Perroud, Anup Singh. |
Other research interests: surface coatings, polymer monoliths, polymer chemistry, photopatterning, bioseparations, and the fluid mechanics of small-scale flows. |
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