SARS-CoV-2 Detection Using Reverse Transcription Strand Invasion Based Amplification And A Portable Compact Size Instrument

Abstract

Rapid nucleic-acid based tests that can be performed by non-professionals outside laboratory settings could help the containment of the pandemic SARS-CoV-2 virus and may potentially prevent further widespread lockdowns. Here, we present a novel compact portable detection instrument (the Egoo Health System) for extraction-free detection of SARS-CoV-2 using isothermal Reverse Transcription Strand Invasion Based Amplification (RT-SIBA). The SARS-CoV-2 RT-SIBA assay can be performed directly on crude oropharyngeal swabs without nucleic acid extraction with a reaction time of 30 minutes. The Egoo health system uses a capsule system, which is automatically sealed tight in the Egoo instrument after applying the sample, resulting in a closed system optimal for molecular isothermal amplification. The performance of the Egoo Health System is comparable to the PCR instrument with an analytical sensitivity of 25 viral RNA copies per SARS-CoV-2 RT-SIBA reaction and a clinical sensitivity and specificity between 87.0-98.4% and 96.6-98.2% respectively.

Nucleic Acid Amplification‐Based Technologies (NAAT)—Toward Accessible, Autonomous, and Mobile Diagnostics

“…In addition to LAMP and RPA other amplification methods including strand invasion-based amplification (SIBA), [59] nucleic acid sequence-based amplification (NASBA), [60] Rolling circle amplification (RCA), [61] helicase-dependent amplification (HDA), [62] and Nicking enzyme amplification reaction (NEAR) [63] have been developed and shown promise toward application in diagnostic assays. Rosenstierne et al developed a compact portable detection instrument called the Egoo health system and used it for extraction-free detection of SARS-CoV-2 using RT-SIBA (Figure 6a).…”

“…Rosenstierne et al developed a compact portable detection instrument called the Egoo health system and used it for extraction-free detection of SARS-CoV-2 using RT-SIBA (Figure 6a). [59] The assays were performed directly on crude oropharyngeal swabs with a reaction time of 30 min. The sensitivity of the device was reported as 25 RNA copies of SARS-CoV-2 with specificity between 96.2% and 98.2%.…”

“…Reproduced under the terms of the CC-BY license. [59] Copyright 2021, The Authors, published by Nature publishing group. b) miSHERLOCK, CRISPR-based diagnostics on a low-cost, portable diagnostic platform with on-platform extraction, purification, concentration, amplification, and detection of viral RNA from unprocessed samples.…”