Multiple Cross Displacement Amplification Linked with Nanoparticles-Based Lateral Flow Biosensor in Screening of Hepatitis B Virus in Clinical Application.

Background: Hepatitis B virus (HBV) is a common pathogen that predominantly causes severe liver disease, and remains one of a huge challenge worldwide, especially in many resource-constrained areas. Developing a low-cost, sensitive, specific, and rapid approach for screening HBV is critical for its treatment and prevention. In the current study, a novel molecular detection approach, multiple cross displacement amplification (MCDA) coupled with polymer nanoparticle-based lateral flow biosensor (MCDA-LFB), was applied for detection of HBV in blood samples.

Methods: HBV standard substance and clinical donor serum samples were collected and used for the establishment and confirmation of the HBV-MCDA-LFB assay. A set of 10 MCDA primers was designed according to HBV-specific gene . The HBV-MCDA-LFB assay conditions, including genomic template concentration, MCDA reaction temperature and time were optimized. The sensitivity and specificity of the HBV-MCDA -LFB assay were evaluated in this report. The HBV-MCDA-LFB assay was applied to detect the HBV agent from clinical samples.

Results: The HBV-MCDA primers based on the gene were valid for establishment of MCDA assay. The HBV-MCDA reaction with optimized conditions could be carried out at a constant temperature 64°C for 35 min. The whole process, including sample preparation (5 min), genomic template extraction (~30 min), MCDA amplification (35 min), and LFB reading (~2 min), could be completed within 80 min. The sensitivity of this assay was 5 IU per reaction. The specificity was 100% for HBV-MCDA-LFB assay.

Conclusion: These results confirmed that the HBV-MCDA-LFB is a low-cost, sensitive, specific, simple, and rapid method for detecting HBV agents. This technique has great potential to develop a point-of-care testing (POCT) method in clinical practice, especially in endemic and resource-constrained regions.