Development and evaluation of the automated multipurpose molecular testing system PCRpack for high-throughput SARS-CoV-2 testing

Abstract

Accurate and fast molecular testing is important for the diagnosis and control of COVID-19. During patient surges in the COVID-19 pandemic, laboratories were challenged by a higher demand for molecular testing under skilled staff shortages. We developed an automated multipurpose molecular testing system, named PCRpack, for the rapid, high-throughput testing of infectious pathogens, including SARS-CoV-2. The system is provided in an all-in-one package, including a liquid handling instrument, a laboratory information management system, and other materials needed for testing operation; is highly customizable; and is easily implemented. PCRpack showed robust liquid handling performance, high clinical diagnostic performance, a shorter turn-around time with minimal hands-on time, and a high testing capacity. These features contribute to the rapid implementation of the high-performance and high-throughput molecular testing environment at any phase of the pandemic caused by SARS-CoV-2 or future emerging pathogens.

Keywords: COVID-19; RT-PCR; SARS-CoV-2; automation; liquid handling instrument.

Fig 1

Components of the PCRpack system. The negative pressure clean booth has casters and is movable. The dimensions of the system are a height of 2,063 mm, width of 1,256 mm, and depth of 990 mm. The system requires two independent power supplies of 100 V and 15 A: one for the clean booth, including the liquid handler and laboratory information management system, and the other for the PCR instrument.

Fig 2

The workflow of the PCRpack system. The workflow was divided into six procedures, and each procedure included several test steps. A broken line between steps indicates that the below and above steps were performed simultaneously. Panels A to D are provided to explain the steps indicated by the characters within parentheses. In the “transfer samples to PCR plate” step (panel C), a maximum of 94 samples were transferred from specimen tubes to a temporary deep-well plate and then transferred from the deep-well plate to a 96-well PCR plate. After dispensing controls into the 96-well PCR plate, the system can be paused to perform a visual inspection of the 96-well PCR plate to verify the dispensing of reagents and samples.

Fig 3

Comparison of test times for each test step between the PCRpack and manual testing methods. Panel A shows the total elapsed time, and panel B shows the hands-on time. The raw data are available in Dataset S2.