Field assay portability of pathogen and contaminant detection
Chemical and biological contaminants on FDA-regulated products pose a serious threat to public health. With increasing public awareness of the risks of chemical and biological contaminations in FDA regulated medical products, FDA aims to provide protocols for rapid screening and identification using high throughput measurements to ensure public health and safety. One such tool for addressing this need is a field-deployable mass spectrometry device capable of providing detailed product characterization information. Field portability of contaminant and pathogen detection is potentially a technology-based game changer because such testing could be performed at portable sites or at limited-resource field clinics. The field portable capabilities we are exploring are field methods for: 1) a polymerase chain reaction (PCR)-based detection of a model pathogen, and 2) mass spectrometry-based detection of chemical contaminants.
The field-portable Palm PCR.
MTE 50 portable mass spectrometer: configured with paper spray ionization for sample introduction.
Currently we have a commercially available miniature PCR- instrument and are optimizing the field methods to detect Salmonella typhimurium and other bacteria in the absence of refrigeration or electricity. We are developing experimental protocols and sourcing reagents that do not require refrigeration, allowing the detection technology to function in any environment with an available cell phone. As a model, we demonstrated recovery of Salmonella spiked into spinach and will focus next on pathogens found on re-used medical devices. We also have a portable miniature mass spectrometer capable of recognizing a contaminant's mass spectral fingerprint to provide detection specificity within seconds. With the aid of ambient ionization techniques such as paper spray ionization, we have demonstrated the capabilities of this portable mass spectrometric technique in screening of chemical contaminant such as adulterated heparin and glycerin-containing medical products. The portable approach bridges FDA’s regulatory screening missions and modern scientific knowledge with the goal of sensing and response infrastructure for potential catastrophic events.
Rosalie Elespuru, Ph.D.
Xing Tang, Ph.D.
Samanthi Wickramasekara, Ph.D.
Berk Oktem, Ph.D
George Washington University