Successful implementation of efficient biodefense surveillance systems depends on several critical factors, according to Helge Lubenow, Ph.D., director of R&D for nucleic acid purification at Qiagen.
"Effective and reliable methods for sample collection, isolation, detection, and identification of potentially pathological agents are crucial in the determination of the severity of diseases such as anthrax, botulinum, and cholera," says Dr. Lubenow, who spoke at Cambridge Healthtech's (www.healthtech.com) Systems Integration in Biodefense Conference in Washington, DC, in August.
In Dr. Lubenow's opinion, standardized systems characterized by a simple uniform workflow ensure minimal operator training and increase process safety and reliability. Flexible automation systems further increase efficacy, avoid any sample-to-sample variation, and minimize human contact to minimize operator risk.
"A major system requirement in biodefense diagnostics is the absence of any false negative results (failing to detect an agent in a threat scenario) as well as the absence of false positives, [to avoid] provoking an emergency response and false alarm," adds Dr. Lubenow.
"Biodefense-related research and diagnostics in surveillance therefore requires robust, easy-to-use, standardized, and validated procedures to be able to achieve highest reliability, sensitivity and selectivity required."
Dr. Lubenow maintains that Qiagen employs a set of technologies and formats that are fully compatible with the requirements defined by the major technology trends in biodefense today: process integration, system integration, and microfluidics to enable preparedness.
These technologies, from preanalytics to analytical reagents (chromatography, selective adsorption, filtration, magnetic particle-based selective adsorption, thin membrane technology, hybrid capture, endotoxin removal, whole genome amplification, and real-time PCR), generate highly efficient, validated processes for sample collection, stabilization, and prepararation for the isolation of pure nucleic acid and protein analytes, according to Dr. Lubenow.
Qiagen has instrumentation for sample purification suiting different throughput needs. For example, a low throughput, portable system (the BioRobot EZ1) is employed in research as well as in confirmation testing during sureveillance.
Higher throughput systems, like the BioRobot universal system, can be used during assay development and validation.
"Our expertise in automation makes us a competent companion for the system integration partners developing highly integrated surveillance systems. Sample preparation technologies are available for the purification of both bacterial and viral agents, in manual as well as automated formats," notes Dr. Lubenow.
DNA purification incorporating a chaotropic salt has been used extensively across a range of application areas, according to John Leaton, of Valco Instruments (www.vici.com). The DNA of interest can be isolated because of its ability to bind silica in the presence of high concentrations of chaotropic salts.
"Chaotropic" refers to a compound's ability to disrupt the regular hydrogen bond structures in water, thus affecting the secondary structure of polymers such as DNA, RNA, and proteins, as well as increasing the solubility of nonpolar substances in water. While denaturing proteins, they do not denature DNA or RNA.