Pooled RNA extraction and PCR assay for efficient SARS-CoV-2 detection

Roni Ben-Ami; Agnes Klochendler; Matan Seidel; Tal Sido; Ori Gurel-Gurevich; Moran Yassour; Eran Meshorer; Gil Benedek; Irit Fogel; Esther Oiknine-Djian; Asaf Gertler; Zeev Rotstein; Bruno Lavi; Yuval Dor; Dana G Wolf; Maayan Salton; Yotam Drier

The first pooling strategy is a simple two-stage testing algorithm known as Dorfman pooling [22] . In the first stage, the samples are divided into disjoint pools of n samples each, and each such pool is tested. A negative result implies that all samples in the pool are negative, while a positive result implies that at least one sample in the pool is positive. In the second stage, the samples of each pool that tested positive are individually tested. While such approaches for SARS-CoV-2 have been recently suggested (e.g. [16, 17] ), we have tested direct pooling of lysates of clinical nasopharyngeal samples, with RNA extraction already performed on the pooled samples. First, we tested the pooling of 184 consecutive samples into 23 pools of 8 samples each, and also tested in parallel each sample individually. This approach yielded highly accurate results, with no loss of diagnostic assay sensitivity: