Automated wash and reuse of disposable pipette tips in a SARS-CoV-2 RT-qPCR diagnostic pipeline

ABSTRACT

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic caused by global shortages in laboratory consumables, in particular for automated PCR. The Technical University of Denmark supported Danish hospitals from 2020 to 2022, conducting SARS-CoV-2 RT-qPCR on around 10,000 patient samples daily. We encountered shortages of disposable pipette tips used with automated liquid handlers that transferred oropharyngeal swab samples to plates before RNA extraction. To enable tip reuse, we developed an automated protocol for washing tips with a 0.5% sodium hypochlorite solution. This effectively eliminated carry-over of genomic material and the wash solution remained effective when stored in an open reservoir at ambient temperatures for 24 hours. A three-day validation setup demonstrated the robustness of the wash protocol. By reducing the number of tips used for transferring samples to 96-well plates from 96 to 8 tips, we mitigated the impact of tip shortages, lowering costs and minimizing plastic waste generation.