Due to the ongoing Corona pandemic, there has been a massive increase in demand for SARS-CoV-2 molecular testing. Due to shortages of SARS COV-2 RT-PCR tests in the early phase of the pandemic, many veterinary laboratories, such as the AGES Institute for Animal Disease Control, were involved in RT-PCR testing of human samples. Opportunities to increase sample throughput while saving valuable consumables were pursued. In 2020, a study was published showing the economic advantages of sample pools. A potential disadvantage of pooling is that infected individuals with very low viral loads could be missed due to dilution of the analyte. In addition, the pooling process itself carries the risk of sample mix-up. Nevertheless, pooling was used early on for retrospective screening of large numbers of individuals in the United States. Since then, a number of publications have addressed the pooling issue, some of which have tested only selected pool sizes (e.g., pools of five or ten samples), while others have tested a broader range of possible pool sizes. The latter is particularly important because the optimal pool size depends on the sensitivity of the assay and the assumed virus prevalence in the sampled population. Here, we present experimental data demonstrating the impact of pool size on detection of samples with widely varying viral loads and show that the pooling approach can be readily implemented in the laboratory, as evidenced by a partially blind pooling experiment.
Last updated: 14.09.2022