TABLE 2.
Comparison of SARS-CoV-2 RT-LAMP solutions, including key parameters on clinical validation.
| Commercial name or acronym | Sample source | Transport medium | Target | Internal control | RNA extraction | Kit/output | Program | Sensitivity/specificity | LoD | Clinical sample tested | Local | References |
| OmniLAMP | Nasopharyngeal | VTM | N, E and RdRp genes | NA | Yes | NEB #M1800; #M1804 Color | 65°C/30 min | 100%/100% Up to RT-qPCR Ct value 30 | 20 copies/μL using clinical samples | 467 | CT-Vacinas-Fiocruz/UFMG, Belo Horizonte, Brazil | This study |
| Nasopharyngeal | Saline | N gene and ORF1a | Human actin B gene | No | NEB #M1800 Color | 65°C/30 min | 87.5%/100% | 25 copies/μL | 62 | Massachusetts General Hospital, Boston, MA, United States | Anahtar et al., 2021 | |
| Yes | 90%/100% | 40 | ||||||||||
| NI | NI | N gene; ORF1ab | NI | Yes | NEB #M1800 Color | 65°C/30 min | 100%/100% | 240 copies/Rx | 62 | Paraná Central Laboratory, Curitiba, Brazil | Aoki et al., 2021 | |
| Saliva | NA | N gene | NI | No, heated | NI | 63°C/30 min | 78.9%/100% | NI | 244 | Sírio-Libanês Hospital, São Paulo, Brazil | Asprino et al., 2020 | |
| Nasal | NI | N gene | NI | Yes | NEB #M1800 Color | 65°C/30 min | NI | 10–7 (equivalent to Ct 34 in RT-PCR) | 14 | National Medical Center, Republic of Korea | Baek et al., 2020 | |
| ALERT | Nasal, saliva | PBS | N gene | BPIFA1 gene | Yes or without extraction (lysate samples) | NEB Bst 3.0 and RTx; #M1800 Fluorescence | 63°C/45 min | 95%/97%–100% | 2 copies/μL | 47 | Hôpital Saint Louis, Paris, France; Pontifica Universidad Católica, Santiago, Chile | Bektaş et al., 2021 |
| Throat and nasopharyngeal | UTM | N gene; | NI | No (lysate samples) | NEB #M1800 | 65°C/30–40 min | 71.15%/96.77% (30 min) 76,9%/96/77% (35 or 40 min) | NI | 180 | Rambam Health Care Campus, Haifa, Israel | Ben-Assa et al., 2020 | |
| LAMP-OSD | Nasopharyngeal and oropharyngeal and SARS-CoV-2 spiked saliva | N gene; ORF1ab (NSP3 and RdRp genes) | NI | Yes | NEB Bst 2.0 polymerase; WarmStart RTx + betaine and additional MgCl2 + FAM Fluorescence | 65°C/90 min | NI | 10 copies/Rx | NA | NA | Bhadra et al., 2021 | |
| Cap-iLAMP | Gargle lavage | NA | N gene; ORF1ab | No, heated samples | NEB #M1800 Color + SYTO9 Fluorescence | 65°C/25–30 min | 97,1%/ | 500 copies/Rx | 192 | NI | Bokelmann et al., 2021 | |
| Nasopharyngeal and oropharyngeal | BD UVTM | N gene and E gene | Human actin B gene | Yes | NEB #M1800 Color + QuantiFluor (Fluorescence) | 65°C/30–40 min | 95.6%/99.2% | 8 copies/μL | 857 | New York Presbyterian Hospital Weill Cornell Medical Center, NY, United States | Butler et al., 2020 | |
| COVID-19-LAMP | Nasopharyngeal, sputum, and throat | ORF3a, E gene | NI | Yes | NEB colorimetric WarmStart | 63°C/60–90 min | 98.2%/100% | 42 copies/Rx | 223 | University of Hong Kong Hospital, China | Chow et al., 2020 | |
| Nasal and oral | PBS | ORF1a | human 18S RNA | Yes | NEB colorimetric WarmStart | 63°C/30 min | 93.8%/90.4% | 100 copies/Rx up to Ct 35 | 466 | Erasto Gaertner Hospital, Curitiba, PR, Brazil | de Oliveira Coelho et al., 2021 | |
| Nasopharyngeal | SPS | N gene and ORF1ab | NI | Yes | NEB Bst 2.0, 3.0, RTx WarmStart +EvaGreen Color and Fluorescence | 8.3%–100%/100% | 200 copies/Rx | University Hospital of Salamanca, Spain | García-Bernalt Diego et al., 2021 | |||
| Nasopharyngeal | UTM, VTM or PBS | ORF1a | NI | No | NEB #E1700 Fluorescence | 63°C/40 min | 81%/100% | 62.5 copies/μL | 137 | University of Wisconsin – Madison Hospital and Clinics, United States | Dudley et al., 2020 | |
| Penn-RAMP RPA+ LAMP | Nasal (spiked samples) | NA | ORF1ab | NI | NA | OptiGene Isothermal Mastermix (ISO-001) + EvaGreen dye Loopamp 2019-SARS-CoV-2 Detection Reagent Kit (Eiken Chemical, Tokyo, Japan) + Leuco Crystal Violet | 63°C/50 min | 100%/NI | 7 copies/Rx | NA | NA | Song et al., 2021 |
| Saliva; throat and nasal | VTM | N gene | NI | No, chelating agent treatment | NEB Color | 65°C/30 min | 90%100% | 105 copies/mL | 62 | Rambam Health Care Campus in Haifa, Israel | Flynn et al., 2020 | |
| OptiGene COVID-19 RT-LAMP | Nasopharyngeal | VTM | ORF1a | NI | Yes, also tested without RNA extraction | OptiGene GspSSD 2.0 Opti-RT Fluorescence | 65°C/20 min | 97%/99% | 100–200 copies/Rx | 196 | Hampshire Hospitals NHS Foundation Trust, United Kingdom | Fowler et al., 2021 |
| Nasopharyngeal | VTM | ORF1a, ORF8, S and N genes | No | NEB Bst 2.0 +EvaGreen Fluorescence | 65°C/60 min | 100%/100% | 50 copies/μL | 20 | OSF Healthcare. Peoria, IL, United States | Ganguli et al., 2020 | ||
| Nasopharyngeal | NI | N gene | NI | Yes | NEB #M1800 Color +EvaGreen Fluorescence | 65°C/50 min | NI | 625 copies/Rx | 14 | Hospital Alfa Medical Center, Guadalupe, México | González-González et al., 2021 | |
| Throat | VTM | ORF1ab, S gene and N gene | Human actin B gene | Yes | NEB #M1800 Color | 65°C/30 min | NI | 2 copies/25 μL | 16 | Shenzhen Luohu People’s Hospital in China. | Huang et al., 2020 | |
| Nasopharyngeal | BD UVTM | NI | NI | Yes | SARS-CoV-2 detection kit (Eiken Chemical Co.) Turbidimetry Fluorescence | 62.5°C/35 min | 56.6%/98.4% | 6.7 copies/Rx | 124 | University Hospital, Japan | Inaba et al., 2021 | |
| Nasopharyngeal | NI | NI | NI | Yes | Loopamp 2019-SARS-CoV-2 Detection Reagent Kit (Eiken Chemical, Tokyo, Japan) Turbidity | 62.5°C/35 min | 100%/97.6% | 101 copies/μL | 76 | National Institute of Infectious Diseases, Japan | Kitagawa et al., 2020 | |
| EasyCOV | Saliva | VTM | NI | NI | No | NEB E1700 + 1 M betaine/fluorescence | 65°C/30 min | 72.7%/95.7% | Equivalent to Ct 35 in RT-PCR | 123 | Montpellier University Hospital, France | L’Helgouach et al., 2020 |
| Saliva | Saline | N-A gene | NI | No, heat + Prot. K lysis | NEB #M1800 Color | 62.5°C/30–60 min | NI | < 10 copies/μL (200 copies/Rx) | 5 | Washington University School of Medicine; Barnes-Jewish Hospital; the Institute of Clinical and Translational Sciences; Tissue Procurement Core, United States | Lalli et al., 2021 | |
| Throat | NI | N gene | NI | Yes | NEB Bst 3.0; WarmStart RTx; Q5 HF DNA polymerase Color or fluorescence | 62.5°C/30–40 min | Sensitivity was 100% for 393 copies/Rx; 80% for 79 copies/Rx and 60% for 16 copies/Rx | 118.6 copies/25 μL or 4.7 copies/μL | 56 | Nantong Third Hospital, China | Lu et al., 2020 | |
| Nasopharyngeal and throat | NI | RdRp | NI | Yes | NEB #M1800 Color | 65°C/60 min | 95.74%/99.95% | 25 copies/Rx | 2,120 | Ramathibodi Hospital, Mahidol University, Bangkok, Thailand | Nawattanapaiboon et al., 2021 | |
| Nasopharyngeal | VTM | ORF1ab | NI | Yes, magnetic bead extraction | MicrosensDx RapiPrep | 65°C/25 min | 80%/100% | Not determined | 21 | National Health Service Care Home, United Kingdom | Österdahl et al., 2020 | |
| SARS-CoV-2 isolated from MRC-5 infected cells | NA | NSP3 gene (ORF1ab) S gene; N gene | NI | Yes | NEB Bst 3.0; + SuperScript IV RT Invitrogen + or leuko–crystal violet Color NEB #M1800 + SYTO-9 Fluorescence | 69°C or 65°C/30 or 60 min | NI | 100 copies/Rx or 10–6 RNA dilution | NA | NA | Park et al., 2020 | |
| Saliva, nasal and nasopharyngeal | Saline | ORF1ab (As1/1e); ORF1a-C and N gene | NI | No | NEB #M1800 and #E1700 Color and fluorescence | 65°C/30–60 min | NI | 1 copy/μL | NA | NA | Rabe and Cepko, 2020 | |
| LAMP-BEAC | Nasopharyngeal and saliva | NI | E, N genes; Orf1ab (As1/1e); | Human statherin mRNA | No, TCEP/EDTA and heat treated | NEB #E1700 and labmade Bst FL Fluorescence | 60°C–65°C/45 min | NI | More than 100 copies/μL | 82 | NA | Sherrill-Mix et al., 2021a |
| Nasal and nasopharyngeal | Amies medium | ORF1a and N gene | NI | Yes | NEB #M1800 Color | 65°C/30 min | 100%/99.7% up to Ct 25 | 100 copies/Rx or 4 copies/μL | 792 | University Hospital Heidelberg and municipal COVID-19 testing station, Germany | Thi et al., 2020 | |
| Dry swab | No, heat treated or directly included in LAMP reaction | 65°C/30 min | 90.5%/99.5% up to Ct 25 in RT-PCR (hot swab) | 343 | ||||||||
| 93.8%/94.1% up to Ct 25 in RT-LAMP (direct swab) | 235 | |||||||||||
| One-pot RT-LAMP | NA | NA | N gene | NA | pUC57-N gene (synthetic) | NEB Bst 3.0 DNA/RNA polymerase + EvaGreen +Rox Fluorescence | 59°C/50 min | NI | 6 copies/μL | NA | NA | Wang, 2020 |
| Nasopharyngeal | VTM | ORF1ab | NI | No | NEB #M1800 Color | 63°C/30 min | 75%/100% | 2.5 copies/uL Spiked samples on VTM | 20 | Columbia University Irving Medical Center | Wei et al., 2021 | |
| Respiratory swabs and bronchoalveolar lavage fluid | ORF1ab and S gene | NI | Yes | Loopamp? 2019-SARS-CoV-2 Detection Reagent Kit (Eiken Chemical, Tokyo, Japan) Turbidity or fluorescence (+ calcein) | 63°C/18–60 min | 100%/100% | 20–110 copies/Rx | 130 | PLA General Hospital, Beijing, China | Yan et al., 2020 | ||
| iLACO | Respiratory (not detailed) | NI | ORF1ab | NI | Yes | NEB #M1800 Color | 65°C/ ≥20 min | 89.9%/NI | 10 copies/μL (detection threshold of 60 copies/μL); equivalent to 35–37 Ct in RT-PCR | 248 | Shenyang province, China | Yu et al., 2020 |
| Respiratory swabs (not detailed) | VTM | N gene and ORF1a | NI | Yes | NEB #M1800 + SYTO-9 Color and fluorescence | 65°C/30 min | NI | 4.8 copies/μL | 6 | Wuhan Institute of Virology, China | Zhang et al., 2020a | |
| Synthetic SARS-CoV-2 RNA | NA | N gene; E gene and As1e gene (ORF1a) | Human actin B gene | Yes | NEB #M1800 + SYTO-9 Color and fluorescence | 65°C/20 min | 87.5% | 2 copies/μL | NA | NA | Zhang et al., 2020b |
NEB #M1800, WarmStart Colorimetric RT-LAMP 2 × Master Mix; NEB #E1700, WarmStart LAMP kit (DNA and RNA); RdRp, RNA-dependent RNA polymerase (harbored by ORF1ab SARS-COV-2 genome region); NI, noninformed; NA, not applied; UTM, Universal Transport medium; VTM, viral transport medium, commonly containing, Hank’s balanced salt solution at pH 7.4 containing BSA (1%), amphotericin (15 μg/mL), penicillin G (100 units/mL), and streptomycin (50 μg/mL); Prot K, proteinase K; BD UVTM, Becton–Dickinson Universal Viral Transport Media system; SPS, sample preservation solution; QuantiFluor, Promega system for dsDNA quantification using a DNA intercalating dye; Prot. K, proteinase K; Cps, copies; Rx, reaction; RdRp, RNA-dependent RNA polymerase; LoD, limit of detection; and BPIFA1, bactericidal/permeability-increasing fold-containing family A1.