Biodefense and Environmental Resources
In the biodefense and environmental areas, two speakers will address new resources that may play important roles. The Biodefense and Emerging Infections Research Resources Repository (BEI Resources) is a source of high-quality materials for research related to biodefense and emerging infections, explains Susan Jones, Ph.D., who refers to the organization as an untapped resource.
BEI Resources was established by the NIAID and is managed by the ATCC (American Type Culture Collection). Its purpose is to serve the scientific community by ensuring secure access to biodefense and emerging infections-related materials for basic research as well as for the development of vaccines, therapeutics, and diagnostics.
To do so, it acquires, authenticates, preserves, and distributes—free of charge—biological materials needed to carry out reproducible research on potential bioterrorism agents and emerging infectious disease agents. This includes microorganisms (bacteria, viruses, and protozoa) as well as specialized biological reagents such as antigens/antibodies, genomic DNA, peptides and proteins, peptide arrays, mutant libraries, and toxins. BEI Resources scientists conduct in-house and collaborative research and aid researchers by providing enhanced authentication and validation details for reagents supplied by BEI Resources. The repository is projected to grow in coming years.
The rapid identification of harmful organisms has also become an important priority in fields such as clinical diagnosis and environmental surveillance. Based on continuing research with Baochuan Lin, Ph.D., at the U.S. Naval Research Laboratory, postdoctoral fellow Marie Archer, Ph.D., will describe “Silicon Microstructures: A New Approach for Molecular Biology Applications.”
The objective of Dr. Lin’s research team is ultimately to develop a portable and highly automated device that could be used in locations that have no dedicated lab space for making nucleic acid analyses. Units currently on the market are limited in terms of the targets they can detect, Dr. Lin states.
Since organisms possess a particular genetic signature, they can be identified by their nucleic acid sequence. For this purpose, the nucleic acids have to be extracted from a cell lysate using a solid phase before any further downstream processing. Silicon is an ideal candidate for this purpose given its integration capabilities and the possibility to chemically modify its surface, Dr. Archer says. The surface area of the silicon solid phases can be tailored through micromachining and electrochemical etching to produce structures with large surface areas and feature sizes ranging from microns to nanometers.
The roughness of the surface is an important factor in solid phases as it increases the effective surface area but it is a complicating factor as well because it makes it more difficult to know the true surface area. The development of these types of solid phases requires an interdisciplinary effort between materials science, chemistry, and molecular biology to address the variables that affect performance.
Both nonselective and selective solid phases are fabricated with silicon microstructures. Nonselective solid phases are used to separate the nucleic acids from other components that can interfere with downstream processes. This separation is not based on the nucleic-acid sequence, the researchers note, but rather on their intrinsic electric charge, which allows them to interact electrostatically with a charged surface via ionic groups such as hydroxyl and amino groups. After electrostatic bonding, extraneous cell parts are washed away.
Selective solid phases are used to separate a particular nucleic acid from a population containing various types. In work to date, the team has used adeno and influenza viruses as well as human genomic DNA. Selective separation is based on the recognition of one nucleic acid sequence, used as a probe, by its matching partner or complementary sequence. The goal is to broaden the procedure to identify any target and multiple organisms.