Diagnosis of SARS-CoV-2 infection with LamPORE, a high-throughput platform combining loop-mediated isothermal amplification and nanopore sequencing

LamPORE is a novel diagnostic platform for the detection of SARS-CoV-2 RNA that combines loop-mediated isothermal amplification with nanopore sequencing, which could potentially be used to analyse thousands of samples per day on a single instrument.

We evaluated the performance of LamPORE against RT-PCR using RNA extracted from spiked respiratory samples and from stored nose and throat swabs collected at two UK hospitals.

The limit of detection of LamPORE was 7-10 genome copies/microlitre of extracted RNA. This is above the limit achievable by RT-PCR but was not associated with a significant reduction of sensitivity in clinical samples.

Positive clinical specimens came mostly from patients with acute symptomatic infection, and among these LamPORE had a diagnostic sensitivity of 99.1% (226/228 [95% CI 96.9-99.9%]). Among negative clinical specimens, including 153 with other respiratory pathogens detected, LamPORE had a diagnostic specificity of 99.6% (278/279 [98.0-100.0%]). Overall, 1.4% (7/514 [0.5-2.9]) of samples produced an indeterminate result on first testing, and repeat LamPORE testing on the same RNA extract had a reproducibility of 96.8% (478/494 [94.8-98.1]).

This indicates that LamPORE has a similar performance to RT-PCR for the diagnosis of SARS-CoV-2 infection in symptomatic patients, and offers a promising approach to high-throughput testing.