Amplifications were performed with 24 repeats, each containing 50 copies of SARS-CoV-2 RNA, or 8 repeats as NTC using E1 and ACTB primer sets or with additional primer sets. (A) Dual (E1 + ACTB) DARQ LAMP amplification. (B) Dual (E1 + ACTB) DARQ LAMP amplification in the presence of an unrelated primer set (IAV and its QFIP:Fd duplex). (C) Dual (E1 + ACTB) DARQ LAMP in the presence of two unrelated primer sets (IAV and IBV and their QFIP:Fd duplexes). (D)
ACTB detection from conditions in (C). (E) Summary of detection: total number of positives, amplification speed (Cq) and correlation of results by real-time curve and end point scanning.
DARQ: Detection of Amplification by Releasing of Quenching; IAV: Influenza A virus primer; IBV: Influenza B virus primer; LAMP: Loop-mediated isothermal amplification: NTC: No-template control; QFIP: Quencher-modified forward inner primer.