LAMP-LFD: establishment and evaluation of a new diagnostic platform for SARS-CoV-2 rapid detection.

BACKGROUND

This study aimed to establish a rapid detection method for SARS-CoV-2 by integrating loop-mediated isothermal amplification (LAMP) with lateral flow dipstick (LFD) technology.

METHOD: Specific primers targeting the nucleocapsid (N) gene and open reading frame 1ab (ORF1ab) gene of SARS-CoV-2 were designed and labeled with 6-FAM and biotin, respectively. After systematically optimizing key reaction parameters, including primer selection, primer concentration, and LAMP reaction time, the sensitivity, specificity, and clinical applicability of the method were evaluated.

RESULTS

The proposed LAMP-LFD assay enables rapid detection within 30 min with high specificity, accurately identifying the N and ORF1ab genes of SARS-CoV-2 without cross-reactivity with influenza A hemagglutinin gene, influenza B neuraminidase gene, and respiratory syncytial virus M gene. The limit of detection reached 1.892 × 101 copies/μL, showing comparable sensitivity to agarose gel electrophoresis and real-time quantitative reverse transcription PCR (RT-qPCR). The results were consistent across different batches of primers and probes, demonstrating good reproducibility. When compared with RT-qPCR using 114 inactivated throat swab samples, the diagnostic agreement rate reached 95.61%.

DISCUSSION: This study provides technical support for the surveillance and control of SARS-CoV-2 infection.