Advantages of chemiluminescence method for antibody detection of 2019-nCOV

Antibody detection is a powerful supplement to the nucleic acid detection of New Coronavirus (2019-nCoV). The antibody detection kits currently on the market mainly adopt chemiluminescence and colloidal gold. The difference in clinical use of these two methods is an important issue that many clinicians care about.

Recently, Xiaofei Li , Guiming Liu and others from the Laboratory Department of the Third People's Hospital of Kunming City used chemiluminescence kits to test a series of clinical samples at different stages of infection, and evaluated the clinical application value of chemoluminescence detection of new coronavirus antibodies.

The 2019-nCOV antibody assay kit (chemiluminescence method) is based on the principle of double antigen sandwich method to detect the total antibody of the new coronavirus. The chemiluminescent microparticle immunoassay (CMIA) was used to qualitatively detect new coronavirus antibodies in human serum or plasma on Caris system.

First, mix the sample, the magnetic particles coated with the new coronavirus recombinant antigen and the reaction dilution. The new coronavirus antibody in the sample will bind to the magnetic particles coated with the new coronavirus recombinant antigen. After washing, the acridine ester labeled with the recombinant antigen of the new coronavirus was added to form a complex of "new coronavirus recombinant antigen-coated magnetic particles-2019-nCoV antibody-2019-nCoV antigen-labeled acridinium ester". After washing again to remove substances that are not bound to the magnetic particles, the pre-excitation solution and the excitation solution are added. The resulting chemiluminescence signal is then measured and expressed in relative luminescence units. The amount of 2019-nCOV antibody present in the sample is positively correlated with the relative luminescence units detected on the Caris system.

The researchers found that the chemiluminescence kits can recognize all types of 2019 ncov specific antibodies, including IgM, IgG, IgA, etc., while the colloidal gold kits can only recognize 2019 ncov specific IgM or IgG antibodies. In addition, the chemiluminescent method can judge the result by collecting photons and reading the luminescent value, while the colloidal gold method can only judge by naked eyes, which is easily affected by subjective factors. The chemiluminescent method is more sensitive than the colloidal gold method.

In summary, the chemiluminescence method is used for the detection of new coronavirus antibodies with high sensitivity and a high degree of whitening of the detection system, which helps to reduce the workload of medical workers and reduce the risk of detection, and can meet the auxiliary diagnosis needs of clinical cases of new coronavirus infection.