Agent: See Biological agent.
Air sampling: Collecting quantities and types of atmospheric contaminants from a representative sample of air.
Amplicon (PCR): A piece of nucleic acid representing a specific product of the amplification reaction.
Assay: A quantitative or qualitative evaluation of the presence or amount of a given target in a particular sample.
Biological agent: A microorganism (or a toxin derived from it) that causes disease in humans, plants, or animals and is used in bioterrorism or biological warfare.
Biosurveillance: The process of active data-gathering with appropriate analysis and interpretation of biosphere data that might relate to disease activity and threats to human or animal health—whether infectious, toxic, metabolic, or otherwise, and regardless of intentional or natural origin—in order to achieve early warning of health threats, early detection of health events, and overall situational awareness of disease activity.
BioWatch Actionable Result: A determination that occurs when analysis of a filter from a BioWatch sampler indicates the confirmed presence of a target organism’s nucleic acid signature.
BioWatch jurisdiction: A major metropolitan area—which may include one or more city, county, state, or regional decision-making bodies—where BioWatch air samplers are operational.
BioWatch program: An activity funded by the Department of Homeland Security that uses sets of air samplers in more than 30 jurisdictions to collect airborne particles onto filters that are subsequently transported to laboratories for analysis for the presence of genetic material from certain biological agents.
BioWatch system: The collection of operational components (which are themselves systems) that produce information from air sampling and feed it into a public health decision-making process to determine the appropriate response to a BioWatch Actionable Result (BAR).
Detection: The determination or recognition of the presence of an object or state of interest.
Detector: A data collection and processing technology that both collects and evaluates data.
Environmental background panel: In the context of a biological agent detection assay, a set of organisms that may be present in the environment, against which the detection assay is tested to determine whether the assay potentially cross-reacts with nucleic acid from these organisms.
Environmental sampling: In the context of the BioWatch system, physical sampling of the environment around a collector associated with a positive PCR assay result to provide decision makers with additional situational assessment and to inform appropriate response actions.
Environmental surveillance: Monitoring of the environment to evaluate potential exposure to harmful agents and damage to living organisms.
Exclusivity strain panel: In the context of a biological agent detection assay, a set of organisms such as closely related bacterial or viral strains and species, against which the detection assay is tested to determine whether the assay potentially cross-reacts with nucleic acid from these organisms.
False negative: A negative result for a given target when the target is present.
False positive: A positive result for a given target when the target is not present.
Inclusivity strain panel: In the context of a biological agent detection assay, the set of organisms, such as bacterial or viral strains and species, against which the detection assay is tested to determine whether the assay is successfully able to detect nucleic acid from these organisms.
Laboratory Response Network: A national network of local, state, and federal public health, health care, food, agriculture, veterinary, and environmental testing laboratories that provide the laboratory infra-
structure and capacity to respond to biological and chemical terrorism and other public health emergencies.
Limit of detection: The minimum concentration of a substance that an assay can detect above background with a certain degree of statistical confidence probability (frequently with 95 percent confidence).
Monitoring: Periodic or continuous surveillance or testing to determine the presence or level of a substance of interest in various media or in humans, plants, and animals.
Multiplex (PCR assay): A type of PCR assay designed to simultaneously amplify and detect multiple target regions of nucleic acid in a single sample. It is distinguished from procedures that perform one molecular assay at a time (see Singleplex assay).
Nucleic acid signature: Nucleotide sequence that is considered distinctive for an organism, or a subset of organisms, and can be used in testing for the presence of nucleic acid from this organism.
Polymerase chain reaction (PCR): A technique in molecular biology that is used to reproduce enzymatically (amplify) selected sections of DNA. It permits the analysis of any short sequence of DNA (or RNA) without the need for cloning.
Plasmid: A small piece of DNA found within a bacterial cell that is separate from the chromosomal DNA of the organism.
Primer (PCR): A short oligonucleotide that is complementary to part of the target nucleic acid sequence that defines the region that will be selectively amplified by the PCR. During PCR, the primer hybridizes to its complementary sequence and polymerase extends the primer in the amplified region. A pair of primers is used, flanking the target amplification region.
Probe: A short oligonucleotide that is complementary to part of the target region; the probe is labeled in a manner that enables it to detect amplification (e.g., by exploiting fluorescence quenching).
Quality assurance: A comprehensive system and infrastructure that ensures that a program or laboratory meets standards of quality.
Quality control: A process that focuses on the performance of specific testing activities.
Screening: In the context of the BioWatch system, analysis of air sampler filters for a preliminary genetic signature of a particular pathogen.
Sensitivity: The probability that a system will correctly indicate the presence of a particular substance when the substance is present above a certain concentration.
Signature: See Nucleic acid signature.
Singleplex (PCR assay): An assay that is designed to amplify and detect a single target region of nucleic acid per sample. Used in comparison to multiplex PCR assay.
Specificity: The ability to correctly identify the absence of a target substance when it is not present.
Threshold cycle (Ct): In the context of a real-time PCR assay, the cycle number at which the amplification curve crosses a specified threshold level, indicating that amplification of the target region is above a background level. The greater the number of cycles required to cross this threshold, the lower the starting concentration of target nucleic acid in the sample.
Validation: The process of ensuring and documenting that a thing, such as a test, device, or process, fulfills the purpose for which it is intended.
Verification: A process that affirms that a given laboratory can obtain the anticipated results and assay performance from a validated assay.