By Zhuang Yingna and Shao Longfei

BEIJING, July 7 – According to news from the Military Medical Institute (MMI) under the PLA’s Academy of Military Sciences (AMS), former PLA Academy of Military Medical Sciences, the 2019-nCoV IgM/IgG antibody test kit, co-developed by a team from the AMS-MMI and the local enterprise, has recently passed the emergency approval of China’s National Medical Products Administration(NMPA) and obtained the Medical Device Registration Certificate (MDRC).

The new test kit innovatively adopts the layer-by-layer assembly method to prepare the double-layer quantum dot-based nano-fluorescence materials. It uses the novel coronavirus S1 protein as an antigen, resulting in high detection sensitivity and strong specificity. One sample of human serum, plasma or whole blood on the test paper can generate the detection results of two antibodies, IgM and IgG, simultaneously. The results may be qualitatively interpreted through visualization with the help of an ultraviolet fluorescence flashlight, or semi-quantitatively interpreted with a fluorescence detector.

Once infecting the human body, novel coronavirus would first breed in the respiratory system, so whether a person has been infected with the virus could be determined through a nose or throat swab or a nucleic acid testing of phlegm. Sometime through infection, the human body would generate specific antibodies against the virus, of which the IgM that appears earlier would be a diagnostic indicator of acute infection, while the IgG that appears later indicates the middle or late stage, or previous infection. A combined use of nucleic acid testing and antibody detection will raise the detection rate of novel coronavirus infection, particularly sifting out asymptomatic cases more efficiently.

It is learned that the team from the PLA AMS-MMI was also the first to successfully develop the nucleic acid test kit for such particular pathogens as MERS, A/H1N1 flu, human infections of H7N9 avian flu and the Ebola virus. After the COVID-19 epidemic broke out, the team set about emergency R&D immediately and successfully developed the 2019-nCoV nucleic acid test kit (RT-PCR fluorescence probe method). The newly approved 2019-nCoV IgM/IgG antibody test kit (quantum dot-based fluorescence immunochromatography) is another test product developed by the team.