Technical Principles and Application Advantages of Light-Initiated Chemiluminescence Assay in SARS-CoV-2 Antigen Detection

Technical Principles and Detection System

The 2019-nCoV Antigen Detection Kit (Light-Initiated Chemiluminescence Assay) is based on light-initiated chemiluminescence technology (such as AlphaLISA), utilizing the singlet oxygen energy transfer mechanism between photosensitive beads and luminescent beads. During the immune reaction, viral antigens in the sample simultaneously bind to antibodies coated on two types of microspheres, forming an immune sandwich complex. Upon excitation light irradiation, the photosensitive beads generate singlet oxygen, which diffuses to the luminescent beads and triggers chemiluminescence. Quantitative or qualitative analysis of antigens is achieved by detecting the intensity of the light signal. This system does not require traditional enzymatic reactions, avoiding issues such as substrate instability and cumbersome washing steps. The reaction occurs in a homogeneous solution, offering simple operation and shortened detection time.

Performance Advantages Over Traditional Methods

Compared with the currently widely used colloidal gold method, the light-initiated chemiluminescence assay generally demonstrates better sensitivity. Since its signal amplification relies on a high-energy oxygen molecular chain reaction, even trace amounts of antigen can trigger a relatively strong luminescent signal, thereby effectively reducing the risk of missed detection in samples with high Ct values or low viral loads. Meanwhile, this platform supports fully automated chemiluminescence analyzers or dedicated light-initiated chemiluminescence detectors, enabling full-process automation from sample loading to report generation and reducing manual operation errors. In addition, with internal standard calibration and standard curves, semi-quantitative or quantitative analysis of sample antigen concentration can be performed, providing clinicians with auxiliary information for assessing dynamic changes in infected individuals' viral load.

Application Scenarios and Precautions

Light-initiated chemiluminescence assay kits are typically suitable for secondary and higher-level medical institutions, CDCs, or independent clinical laboratories equipped with corresponding detection instruments. During operation, sample collection and processing requirements in the kit instructions (such as nasal swab and throat swab preservation solution volume and storage conditions) must be strictly followed to avoid hemolysis or repeated freeze-thaw cycles affecting test results. It is worth noting that light-initiated signals are susceptible to ambient light interference, and the detection process should be completed under light-protected or low-light conditions. Furthermore, since this methodology is still fundamentally an immunoassay, mutations in the viral S protein or N protein may cause antigenic epitope changes. Manufacturers need to continuously verify the detection performance of reagents against new variants, and users should pay attention to updated applicable virus spectrum information in product instructions.

Conclusion

The 2019-nCoV Antigen Detection Kit (Light-Initiated Chemiluminescence Assay), with its high sensitivity, quantitative potential, and automation compatibility, expands the technical options for antigen detection and is particularly suitable for scenarios with high requirements for detection throughput and accuracy. However, users still need to comprehensively evaluate based on their own laboratory conditions, detection purposes, and cost factors, and select products registered and approved by the National Medical Products Administration (NMPA) under compliance premises.