Garber E.A.E.,U.S. Food and Drug Administration |
Venkateswaran K.V.,Radix Biosolutions, Ltd |
O'brien T.W.,Tetracore Inc.
Journal of Agricultural and Food Chemistry
Detection of proteinaceous toxins in complex heterogeneous mixtures requires highly specific and sensitive methods. Multiplex technology employing multiple antibodies that recognize different epitopes on a toxin provides built-in confirmatory analysis as part of the initial screen and thereby increases the reliability associated with both presumptive positive and negative results. Polyclonal and monoclonal antibodies were obtained for abrin, botulinum toxins, ricin, and Staphylococcus enterotoxins A, B, and C (SEA, SEB, and SEC). Food samples were spiked with the toxins either individually or mixed and analyzed following 40-fold dilution. Abrin, botulinum toxin A complex, ricin, and SEB displayed limits of detection in the original food samples ranging from 0.03 to 1.3 μg/mL, from 0.03 to 0.07 μg/mL, from 0.01 to 0.1 μg/mL, and from <0.01 to 0.03 μg/mL, respectively. Redundancy, that is, multiple antibodies for each toxin, some recognizing different epitopes or displaying different binding affinities, provided a "fingerprint" for the presence of the toxins and built-in confirmation, thus reducing the likelihood of false-positive and false-negative results. Inclusion of internal controls, including a unique protein, helped control for variations in dilution. Paramagnetic microspheres facilitated the detection of analyte in foods containing particulate matter incompatible with the use of filter plates normally used in the wash steps of assays employing standard polystyrene microspheres. © 2010 American Chemical Society. Source
Hestekin C.N.,Northwestern University |
Hestekin C.N.,University of Arkansas |
Lin J.S.,Northwestern University |
Lin J.S.,Stanford University |
And 7 more authors.
Knowledge of the genetic changes that lead to disease has grown and continues to grow at a rapid pace. However, there is a need for clinical devices that can be used routinely to translate this knowledge into the treatment of patients. Use in a clinical setting requires high sensitivity and specificity (>97%) in order to prevent misdiagnoses. Single-strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) are two DNA-based, complementary methods for mutation detection that are inexpensive and relatively easy to implement. However, both methods are most commonly detected by slab gel electrophoresis, which can be labor-intensive, time-consuming, and often the methods are unable to produce high sensitivity and specificity without the use of multiple analysis conditions. Here, we demonstrate the first blinded study using microchip electrophoresis (ME)-SSCP/HA. We demonstrate the ability of ME-SSCP/HA to detect with 98% sensitivity and specificity >100 samples from the p53 gene exons 5-9 in a blinded study in an analysis time of <10min. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Basile A.J.,Centers for Disease Control |
Horiuchi K.,Centers for Disease Control |
Panella A.J.,Centers for Disease Control |
Laven J.,Centers for Disease Control |
And 5 more authors.
Serodiagnosis of arthropod-borne viruses (arboviruses) at the Division of Vector-Borne Diseases, CDC, employs a combination of individual enzyme-linked immunosorbent assays and microsphere immunoassays (MIAs) to test for IgM and IgG, followed by confirmatory plaque-reduction neutralization tests. Based upon the geographic origin of a sample, it may be tested concurrently for multiple arboviruses, which can be a cumbersome task. The advent of multiplexing represents an opportunity to streamline these types of assays; however, because serologic cross-reactivity of the arboviral antigens often confounds results, it is of interest to employ data analysis methods that address this issue. Here, we constructed 13-virus multiplexed IgM and IgG MIAs that included internal and external controls, based upon the Luminex platform. Results from samples tested using these methods were analyzed using 8 different statistical schemes to identify the best way to classify the data. Geographic batteries were also devised to serve as a more practical diagnostic format, and further samples were tested using the abbreviated multiplexes. Comparative error rates for the classification schemes identified a specific boosting method based on logistic regression "Logitboost" as the classification method of choice. When the data from all samples tested were combined into one set, error rates from the multiplex IgM and IgG MIAs were <5% for all geographic batteries. This work represents both the most comprehensive, validated multiplexing method for arboviruses to date, and also the most systematic attempt to determine the most useful classification method for use with these types of serologic tests. Source
Tetracore Inc. | Date: 2008-04-08
Diagnostic test strip or strips for scientific use, comprising an agent for detecting or identifying one or more pathogens; Diagnostic cassette composed of diagnostic test strip or strips for scientific use in detecting or identifying one or more pathogens; Diagnostic testing device for scientific use composed of diagnostic test strip or strips for scientific use in detecting or identifying one or more pathogens; Diagnostic kit, composed of diagnostic test strip or strips for scientific use in detecting or identifying one or more pathogens, and a buffer and vial and a positive control preparation all for scientific and research laboratory use. Medical diagnostic test strip or strips, comprising an agent for detecting or identifying one or more pathogens; Medical diagnostic cassette composed of medical diagnostic test strip or strips, for detecting or identifying one or more pathogens; Medical diagnostic device composed of medical diagnostic test strip or strips for detecting or identifying one or more pathogens; Medical diagnostic kit, composed of medical diagnostic test strip or strips for detecting or identifying one or more pathogens, and a buffer and vial and a positive control preparation for all medical laboratory use and clinical laboratory use.
Tetracore Inc. | Date: 2004-01-27
Diagnostic kits consisting primarily of a testing device, testing strips, disposable sample vials, and associated instructional materials provided therewith, for the detection of harmful microorganisms and biological contaminants, namely, potential biological weapon agents.