DisplayTitle

<div><span>The National Plant Protection Laboratory Accreditation Program (NPPLAP) mission is to expand USDA Plant Protection and Quarantine laboratory capacity and promote continuous process improvement for diagnostics of regulated plant pathogens by accrediting network laboratories, use of validated diagnostic protocols and Proficiency Testing (PT). A type of inter-laboratory comparison, PT is where a blind randomized set of samples that mimic field samples is sent to network laboratories for analysis using approved methods. Therefore, in addition to testing labs’ competency, the PT provides data on methods’ performance by different diagnosticians from different laboratory settings and using different equipment. The NPPLAP PT programs for <i>Phytophthora ramorum</i>, citrus greening and plum pox virus have collected multiyear data on the PPQ approved diagnostic methods from approx. 30 laboratories. Analysis of the PT results has provided invaluable data on critical test parameters such as detection limit, precision and range, and methods’ fitness for intended use. This and participant feedback have allowed NPPLAP to identify needs for improvement of these methods. The PT data supports the NPPLAP planned methods deviation process. This process is applied to demonstrate comparability of modified methods, used by a particular laboratory, with approved PPQ methods. This allows network laboratories to implement updated technology and higher throughput to fit their needs. </span><p> </div>