The Establishment Of "LAMP-Gold Mag Lateral Flow Immunoassay" Method For Detection Of COVID-19

The novel coronavirus named COVID-19 by the World Health Organization is still spreading globally and has seriously threatened human life and health.Combined with the situation of the global COVID-19 pandemic,the prevention and control strategy of " external anti-input,internal anti-rebound" is implemented.The foucus of foreign import prevention is the customs at the port of entry.Therefore,on-site nucleic acid testing should be carried out for people with fever or suspected people entering the country in a timely manner,and timely isolation and treatment should be carried out.Internally,the focus of preventing rebound is to carry out on-site nucleic acid testing for fever crowd and suspected crowd in public places such as airports and stations,as well as fever clinics,and conduct timely isolation and treatment.Therefore,the reagents that can be used for rapid nucleic acid detection on site are of great significance to the implementation of the prevention and control strategy of " external anti-input,internal anti-rebound" at this stage.In this study,based on loop-mediated isothermal amplification(LAMP)and gold magnetic particles as the core carrier,a COVID-19 nucleic acid detection technology called "LAMP-Gold Mag Lateral Flow immunoassay " was established.The technology platform can perform visual interpretation or analysis based on the magnetic signal recognition of gold-magnetic particles through one-step nucleic acid extraction-free amplification combined with Gold Mag Lateral Flow immunoassay system.The entire detection process can be completed within 30 minutes.The study firstly screened and optimizated the primers for the single-plex amplification system of the COVID-19 by combining the Gold Mag Lateral Flow immunoassay system and the loop-mediated isothermal amplification technology with the two detection sites(N,ORF)of the COVID-19;Secondly,the internal standard gene Rnase P was introduced into the loop-mediated isothermal amplification system for double-plex amplification.As an internal reference system,the quality of the sampling and amplification process was controlled and monitored internally,the construction of double " LAMP-Gold Mag Lateral Flow immunoassay " nucleic acid detection system was realized.Finally,the pseudovirus standard was used to evaluate the performance of both single-plex and double-plex amplification systems.The detection technology was identified by magnetic signals,with a sensitivity of 50copies/m L and good specificity.In this study,gold magnetic particles were used as the core carrier,combined with loop-mediated isothermal amplification(LAMP)to establish a dual "LAMP-Gold Mag Lateral Flow immunoassay " nucleic acid detection technology for COVID-19.The detection technology uses Rnase P as the internal standard,and the detection can be completed within 30 minutes by one-step nucleic acid extraction-free amplification,and the detection sensitivity can reach 50 copies/m L.The detection technology has good application prospects for different levels of medical institutions such as customs,airports,stations and other public places.