National Plant Protection Laboratory Accreditation Program

Last Modified: March 29, 2024

The National Plant Protection Laboratory Accreditation Program (NPPLAP) evaluates laboratories that use molecular diagnostics to support PPQ programs to ensure their capability to make accurate diagnostic determinations for regulatory purposes. 

This program also ensures diagnostic capacity for PPQ and establishes a state of readiness to support PPQ emergency programs. To ensure lab capability, NPPLAP accredits USDA regulatory labs, laboratories within the National Plant Diagnostic Network (NPDN), and state agricultural department laboratories to validate proficiency throughout dispersed laboratory network. Proficiency Test Panel are sent yearly to participating analysts within approved labs. This test not only evaluates and verifies the proficiency of the analyst’s technical skills in the lab, but it also measures the overall capabilities of the lab and its personnel to interpret and accurately report proficiency test data. The panel results are returned to the program and evaluated for accuracy and rigor in the processing and reporting of determinations. NPPLAP currently accredits laboratories to diagnose Phytophthora ramorum and the Huanglongbing (citrus greening) pathogen, and certifies laboratory diagnosticians to test for Phytophthora ramorum, citrus greening, and plum pox virus.

NPPLAP also fosters the adoption of new practices and equipment and promotes continuous improvement through functional quality management systems for plant diagnostic labs. Please contact Dr. Pat Shiel, NPPLAP Coordinator, if you have any questions or plan to participate in NPPLAP either by establishing an accredited laboratory in this system (Phytophthora ramorum or citrus greening) or becoming a certified analyst (Phytophthora ramorum, citrus greening, or plum pox virus). Information is also available on request regarding accredited laboratories and Potentially Actionable Suspect Sample (PASS) policies.


Pat Shiel

Laboratory Director


Raleigh, NC