​​​​​​​​Diagnostic Assay Validation Network (DAVN)​

Welcome to the Diagnostic Assay Validation Network (DAVN) – a new community for diagnostic researchers, regulators, and professionals across government, industry, and academia to develop and share standard diagnostic method development and validation within the plant science community.​

The DAVN was created to provide a working space for plant scientists to easily access statistical tools, registries of methods and controls, promote validated methods, and connect with assay deve​lopers, testers, and end-users via an online community (coming soon).

Learn more about the need and the v​​ision for DAVN​.​


​​Upcoming ​Webinars

Advances on CRISPR-based pathogen detection​

Broadcast Date: ​Monday, April 29​, 2024 | 12:00pm - 1:30pm CDT

Clustered regularly interspaced short palindromic repeats (CRISPR, pronounced “crisper”) were first detected in 1987 by Yoshizumi Ishino in Escherichia coli. While at the time, the lack of sufficient DNA sequence data made it impossible to predict their function, advances on sequencing technologies and further studies on sequence similarities allowed scientists to understand how CRISPRs work alongside CRISPR-associated enzymes (Cas) as a system (CRISPR-Cas) to protect prokaryotic cells against invading viruses and plasmids. Further studies on CRISPR-Cas systems led to the invention of CRISPR-Cas9 genome editing technology and the 2020 Nobel Prize in Chemistry awarded to Jennifer Doudna and Emanuelle Charpentier.

In the last few years, scientists have harnessed the power of the CRISPR-Cas system as a tool for the specific detection of pathogens with increased sensitivity and portability. In this webinar we will introduce the process for the design, development, and optimization of different CRISPR-Cas methods for the detection of plant pathogens. Speakers will reflect on best practices, lessons learned and future promise for this technology.
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​​​Webinars on Demand

Isothermal Diagnostics for Critical Plant Pathogens: Design, Development, and Implementation

​​Broadcast date: Thursday, March 14, 2024​ | 1:00pm - 2:3​0pm CDT

Gain a comprehensive understanding of t​he fundamental principles of isothermal amplification techniques, explore real-world case studies that showcase successful applications of isothermal diagnostics in plant pathology, and understand how these techniques have been used to identify and manage plant diseases in diverse agricultural contexts.​​

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

​​​​Broadcast Date: Tuesday, February 6, 2024 | 12:00pm​ - 1:30pm CST

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.​

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Sequence-Based Diagnostic Technology​

Broadcast Date: ​Wednesday, January 24, 2024 | 9:30am - 11:00am CST

This webinar emphasizes use of High Throughput Sequencing (HTS) in pathogen detection and diagnostics, with a focus on sequence data capture, management and pathogen detection. Until recently, HTS has had limited adoption for plant pathogen diag​nosis due to the need for specialized sequencing equipment, not designed for diagnostics. Sequence data can be in the Gigabyte size range, making it difficult to manage and organize for pathogen detection. Early protocols require users to have bioinformatics knowledge and ability to code. This webinar will provide solutions to these constraints by pioneers in the field.

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​​Using RCA for Detecting and Studying Diseases: Examples for Plant DNA Viruses

​​Broadcast Date: December 6, 2023 | 12:00 - 1:00pm Central

This webinar introduces ​the protocol for using RCA to amplify circular DNA, focusing on plant DNA viruses as case studies. It begins with a basic DNA extraction protocol and proceeds to the amplification step using phi 29 DNA polymerase. The resulting DNA will then be ready for various applications, including sequencing, cloning, and diversity analysis. At the end of this webinar, attendees will have an understanding of: 

  • ​the advantages of employing RCA in molecular biology and diagnostic laboratories ​
  • how to explain the DNA amplification procedure and the potential uses of the resulting DNA​

View Now


Resources & ​News

  • Focus Issue: APS has published a DAVN focus issue.  Find the DAVN focus issu​e here​.
  • Webinar: Dr. Carrie Lapaire Harmon (University of Florida) led a DAVN webinar with the National Plant Diagnostic Network on March 1, 2023. You can access the webinar recording here.
  • Survey Results: ​Findings from the ​Specimen Management Plan Community Survey that was conducted by the Biodiversity Collections Network (BCoN)​ and the U.S. ​Culture Collection Network (USCCN) in partnership with the American Institute of ​Biological Sciences and the Natural Science Collections Alliance (published April 11, 2023)​
  • Follow us on Twitter: catch our latest updates​ when you follow us @the_davn


Components of the dashboard coming in 2024:

  • Methods library: designed to help users find appropriate methods more quickly and explain their performance limitations to clientele.
  • Registry of expertise, testers, and end-users: supports development and validation of new assays through ring-testing and continuous improvement through end-use feedback
  • Registry of specimen and insilico cultures and collections and data: supports the development of validated protocols and use of appropriate positive and negative controls in testing laboratories

Research

You can submit your Diagnostic Assay Validation related papers to any APS journal. Publications presenting new or adapted diagnostic tests or assays should clearly state the purpose for which the assay is developed, e.g., surveillance both pre- and post- detection, presumptive identifications, confirmatory diagnostics, regulatory clearance of plant products including seed, germplasm or plants, research, etc.

  • Research manuscripts should give focus to assay validation parameters and explicitly state the purpose of the assay, assay fitness for the purpose, and which of the following validation parameters were addressed and how: analytical specificity, diagnostic specificity, analytical sensitivity, diagnostic sensitivity, repeatability, and reproducibility. Validation parameters should be discussed in the body of the manuscript and reviewed in the discussion section. The validation parameters listed above should be explicitly addressed, including those that were not addressed and why. Click here for more instructions on how to submit a manuscript.

View more instructions on how to submit a manuscript.


Sign up to receive​ DAVN updates​!​

Questions? Contact us at DAVN@scisoc.org



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