SARS-CoV-2 IgM/IgG detection kit is a lateral flow immunoassay which uses europium (III) nanoparticles as the fluorescent marker for the detection and qualitative measurement of IgM and IgG antibodies against the nucleocapsid protein (NP) of SARS-CoV-2 virus in human blood.

The kit is only used as a supplementary test indicator for suspected cases with negative nucleic acid test results of SARS-CoV-2 virus, or used in conjugation with the nucleic acid test in diagnosis of suspected cases of coronavirus disease 19 (COVID-19). It cannot be used as a basis for diagnosis and exclusion of COVID-19, and it is not suitable for screening of general population.

The product is only applicable to medical institutions, and intended for use by professional person.

A positive test result requires further confirmation, and a negative test result cannot rule out the possibility of infection of SARS-CoV-2 virus.

The product is limited to clinical use and emergency storage during the COVID-19 outbreak and cannot be used as a routine in vitro diagnostic reagent for clinical use. The test results of this kit are for clinical reference only. It is recommended to conduct a comprehensive analysis based on the clinical manifestations of patients and other laboratory tests.

Laboratory testing of SARS-CoV-2 virus shall be carried out in accordance with local requirements for biosafety.

The novel coronaviruses belong to the β genus, now officially named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which caused the outbreak of a coronavirus-associated acute respiratory disease called coronavirus disease 19 (COVID-19). COVID-19 is an acute respiratory infectious disease. People are generally susceptible. Currently, the patients infected by the novel coronavirus are the main source of infection; asymptomatic infected people can also be an infectious source. Based on the current epidemiological investigation, the incubation period is 1 to 14 days, mostly 3 to 7 days. The main manifestations include fever, fatigue and dry cough. Nasal congestion, runny nose, sore throat, myalgia and diarrhea are found in a few cases.

Nucleocapsid protein (NP) is the most abundant protein on the helical nucleocapsid of coronaviruses, which envelopes the entire genomic RNA. NP also interacts with other viral structural proteins to play important roles during host cell entry and virus particle assembly and release. Anti-NP antibodies have been shown to be the earliest and the most predominant antibodies detectable in patient’s blood samples after coronavirus infection.

SARS-CoV-2 IgM/IgG detection kit is based on the principle of an immunochromatography in vitro test for the qualitative determination of antibodies against SARS-CoV-2 NP protein. When the sample is added to sample pad, it moves to the conjugate pad and resuspends NP-conjugated europium (III) nanoparticles that are dried on the conjugate pad. NP-conjugated europium (III) nanoparticles bind to anti-NP antibodies in the specimen and form an antibody-NP- europium (III) nanoparticles complex. The mixture moves along the nitrocellulose membrane by capillary action and reacts with anti-human IgM as well as anti-human IgG antibodies that have been immobilized in the test reaction area separately. If antibody against SARS-CoV-2 is present enough in the sample, a fluorescent band in the test reaction area is appeared under UV. If there is no antibody against SARS-CoV-2 or not sufficient in the sample, the area will remain colorless. The sample continues to move to the control reaction area, and forms a fluorescent band, indicating the test is working properly and the result is valid.