Interlaboratory performance and quantitative PCR data acceptance metrics for NIST SRM® 2917

Surface water quality quantitative polymerase chain reaction (qPCR) technologies are expanding from a subject of research to routine environmental and public health laboratory testing. Readily available, reliable reference material is needed to interpret qPCR measurements, particularly across laboratories. Standard Reference Ma-terial (R) 2917 (NIST SRM (R) 2917) is a DNA plasmid construct that functions with multiple water quality qPCR assays allowing for estimation of total fecal pollution and identification of key fecal sources. This study in-vestigates SRM 2917 interlaboratory performance based on repeated measures of 12 qPCR assays by 14 labo-ratories (n = 1008 instrument runs). Using a Bayesian approach, single-instrument run data are combined to generate assay-specific global calibration models allowing for characterization of within-and between-lab variability. Comparable data sets generated by two additional laboratories are used to assess new SRM 2917 data acceptance metrics. SRM 2917 allows for reproducible single-instrument run calibration models across laboratories, regardless of qPCR assay. In addition, global models offer multiple data acceptance metric options that future users can employ to minimize variability, improve comparability of data across laboratories, and increase confidence in qPCR measurements.

Automated summary

Surface water quality qPCR technologies are becoming routine in environmental and public health labs, but the need for reliable reference materials to interpret measurements across labs is crucial. The study investigates the performance of a DNA plasmid construct, SRM 2917, in 12 qPCR assays across 14 different labs. Bayesian analysis is used to generate assay-specific calibration models and assess data acceptance metrics. The results show that SRM 2917 allows for reproducible calibration models and offers options for minimizing variability and improving comparability of data across labs.