Development of a Recombinase Polymerase Amplification Assay for Detection of Epidemic Human Noroviruses

Moore, Matthew D.; Jaykus, Lee-Ann

When applied to heated stool, RT-RPA did not perform as well, but positive signal was still repeatedly produced for all outbreak-derived stool samples except one (sample 44), with estimated input genome concentration ranging from 0. 8-10.0 LGC and positive signal produced in 6.7-20.0 min. For most boiled stool samples, the RT-RPA produced positive signal for samples with high levels of inhibitors. For example, for relatively "dirty" samples (20% and 2% fecal suspensions), RT-RPA produced more positive replicates than did RT-qPCR, with 61% versus 18% positive replicates for 20% stool, and 61% versus 58% for 2% stool, respectively ( Figure S1 ). Supplementation of reactions with dimethyl sulfoxide (DMSO), formamide, and RNase inhibitor did not improve the results of the RT-RPA assay ( Figure S3 ).