Multicenter study evaluating novel multi-specimen pooling assay for the detection of SARS-CoV-2: High sensitivity and high throughput testing

Abstract

Background/purpose: Mass screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important to prevent the spread of coronavirus disease 2019 (COVID-19). Pooling samples can increase the number of tests processed. LabTurbo AIO 48 is an automated platform that allows ribonucleic acid extraction and sample analysis on the same instrument. We created a novel pooling assay on this platform for SARS-CoV-2 detection and demonstrated that the pooling strategy increases testing capacity without affecting accuracy and sensitivity.

Methods: Comparative limit of detection (LoD) assessment was performed on the LabTurbo AIO 48 platform and the current standard detection system based on real-time reverse transcription polymerase chain reaction (rRT-PCR) using 55 clinically positive samples. An additional 330 primary clinical samples were assessed.

Results: Six samples pooled into one reaction tube were detected in approximately 2.5 h using the World Health Organization rRT-PCR protocol. LabTurbo AIO 48 also demonstrated a higher throughput than our reference rRT-PCR assay, with an LoD of 1000 copies/mL. The overall percentage agreement between the methods for the 330 samples was 100%.

Conclusion: We created a novel multi-specimen pooling assay using LabTurbo AIO 48 for the robust detection of SARS-CoV-2, allowing high-throughput results; this assay will aid in better control and prevention of COVID-19. The diagnostic assay was cost-effective and time-efficient; thus, the pooling strategy is a practical and effective method for diagnosing large quantities of specimens without compromising precision.

Keywords: Coronavirus disease 2019; High throughput; Pooled specimen; Severe acute respiratory coronavirus 2.

Figure 1

Schematic diagram of sample pooling strategy for detecting SARS-CoV-2 in clinical samples.

Figure 2

Correlation of Ct values for clinically positive pooled samples from the WHO (followed by Taiwan CDC)-recommended rRT-PCR assay for RdRp gene and the LabTurbo AIO 48 targeting N1 gene for severe acute respiratory coronavirus 2 detection in (a) the Tri-Service General Hospital (TSGH) and (b) Cathay General Hospital (CGH).

Figure 3

Comparative results of the Ct values detected in the pooled sample containing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive samples from two medical centers. p-values were evaluated using Scheffe's method.