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​​​​​Methods And Tools for Plant Pathogen Immunoassay Design, Development and Analysis​

This webinar is organized by the Diagnostic Assay Validation Network (DAVN)​​

Broadcast Date: February 6, 2024 | 12:00 – 1:30 ​PM Central

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​Webinar Summary​

Tools and techniques for nucleic acid-based plant pathogen diagnostic assays currently dominate the scientific literature, while those describing immunoassays have dwindled over the years in number and scope.  This webinar will bring together experts to review classical techniques and describe modern techniques for designing, generating, and applying immunoreagents that are fit for specific diagnostic purposes. In addition, an online APS toolkit will be introduced for the analysis and validation of qualitative diagnostic assays.

Learning Objectives​

This session will review classical techniques and describe modern techniques for designing, generating, and applying immunoreagents in diagnostic assays, and analyzing data outputs from assays. At the end of this session, attendees will understand the biology and biochemistry behind immunoassays, terminology describing antibodies used in assays and various types of diagnostic immunoassays; novel techniques for discovery and design of antibody targets; and various methods for generating natural and synthetic antibodies. Attendees will learn where to access online APS open-source statistical tools and how to apply them to data outputs from immunoassays in plant pathogen diagnostics.​


Deborah Groth-Helms
Agdia Inc.​​​

Deborah (Debi) Groth-Helms is the Director of Testing Services at Agdia Incorporated, a leading provider of plant pathogen detection assays that is headquartered in Indiana. Debi holds a M.Sc. of Biochemistry and Molecular Biology in Agronomy (Purdue University) and has been involved with test validation and application throughout her 16 years at Agdia, from consulting with Research & Development on new tests to leading testing operations for Agdia’s diagnostic laboratory. As Quality Manager, Debi designed and maintains the ISO/IEC 17025 accredited quality program in addition to various other trade and regulatory certifications. She has served as project director and contact for several grant programs at Agdia focused on innovation in qualitative test methodology. Debi currently serves as a consultant for the Diagnostic Assay Validation Network (DAVN) on best practices in assay validation design for successful technology transfers.

Douglas Luster
USDA, ARS, Foreign Disease-Weed Science Research Unit​

Dr. Luster has been Research Plant Physiologist with the USDA-ARS Foreign Disease-Weed Science Research Laboratory at Ft. Detrick, MD since 1988. He served as Research Leader of the ARS Foreign Disease-Weed Science Research Unit from 1997-2015, and RL of the ARS Beneficial Insect Introduction Research Unit from 2009-2016.  

A native of New Jersey, he completed all his higher education in North Carolina, including a B.S. in Marine Biology at the University of North Carolina in 1978, and a Ph.D. in Botany from N.C. State University, awarded in 1984.  He completed Research Associate postdoc positions at the George Washington University and at the USDA-ARS Photobiology Laboratory in Beltsville, MD, on plant membrane enzymes involved in abiotic stresses, before beginning his position at the FDWSRU in 1988.

His research is conducted at the Ft. Detrick laboratory, which houses a BSL-3 plant pathogen containment facility for research on threatening and emerging crop diseases.  Research is focused upon foreign crop diseases. His personal research centers on protein expression in host-pathogen systems, and development of immunoassays to detect emerging pathogens. He recently licensed diagnostic assay reagents for the emerging plant pathogen Phakopsora pachyrhizi, causal agent of Asian soybean rust to a commercial pathogen diagnostics company.​

John Hammond
Floral and Nursery Plants Research
​John Hammond obtained his Ph.D. in plant virology with Roger Hull, purifying and characterizing several viruses infecting Plantago species, including the potexvirus plantain virus X. This was followed by postdoctoral training with Richard Lister at Purdue University, where he improved purification methods for the viruses associated with barley yellow dwarf disease, and prepared high quality polyclonal antisera employed by others for epidemiological surveys and to evaluate cereal cultivar sensitivity to the viruses. He then joined the USDA Agricultural Research Service, in what is now the Floral and Nursery Plants Research Unit, where he still works as a Research Plant Pathologist. Dr. Hammond is a national and international authority on viruses affecting ornamentals, using a range of techniques to purify, detect and differentiate many viruses, and producing reagents adopted for commercial plant virus diagnosis. He also has advanced basic understanding of virus genome structure, accumulation and spread, and the utilization of plant viral vectors. Dr. Hammond has many national and international collaborators, including groups from the United Kingdom, the Netherlands, and Belgium, with whom he showed that the more recently described actinidia virus X was synonymous with plantain virus X, which he had characterized during his doctoral studies.

Ramon Jordan
Floral and Nursery Plants Research

Ramon Jordan is a Supervisory Research Plant Pathologist in USDA’s Floral and Nursery Plants Research Unit (FNPRU), U.S. National Arboretum (USNA), where for the last 40 years, he has conducted a broad-based research program, primarily on the identification and characterization of new and emerging plant viruses of major significance to ornamental and nursery crops and producing reagents and tools for the detection and identification of various plant pathogens, including a patented broad-spectrum reacting McAb [with John Hammond] that was commercialized for the ‘generic’ detection of potyviruses. Collaborative research has led to the development of a Taq-Man qRT-PCR for the detection of pepino mosaic virus, the development of virus-resistant transgenic gladiolus plants expressing either anti-sense viral sequences or anti-viral scFv antibody transgenes, the development of phage display scFv antibodies to Xylella fastidiosa or surface proteins of the citrus HLB pathogen ('Ca. Liberibacter asiaticus'), the detection of new and/or economically important viruses using high-throughput sequencing, and studying the genetic diversity of rose rosette virus. Ramon also served as Research Leader (FNPRU), Acting Director or Associate Director (USNA), and as Associate Editor of Plant Disease and Phytopathology, as a member (and chair) of the APS Virology Committee, as well as on several ICTV Plant Virus Working Groups.​