Real-time colorimetric LAMP methodology for quantitative nucleic acids detection at the point-of-care

Most methods applied to nucleic acids’ detection at the point-of-care require either expensive and mostly bench-top instruments or simpler inexpensive systems providing qualitative results. Truly decentralized approaches to reliable, quantitative and affordable diagnostics are still missing. Here, we report the development of real-time quantitative colorimetric LAMP based on a portable and cost-effective device, the use of which requires minimal training. Main advantages of the method are the rapid analysis time (<30min); quantification over a large dynamic range (9 log units); ability to work with crude samples (saliva, tissue); demonstrated low detection limit (1-10 copies); smartphone-operation and fast prototyping (3D-printing). The system’s broad detection capability is demonstrated during infectious diseases-testing for COVID-19 and pharmacogenetics for BRAF V600E mutation testing. Validation studies showed 97.4% and 100% agreement with qRT-PCR for SARS-CoV-2 RNA detection extracted from positive and negative patients’ samples (89), respectively; and 100% agreement with ddPCR and Sanger sequencing for BRAF V600E mutation detection from 12 clinical biopsy samples. The new methodology provides a needed solution for affordable healthcare at the point-of-care, with emphasis on global diagnostics.